Organizers : National Synchrotron Radiation Research Center (NSRRC), Taiwan National Chiao-Tung University (NCTU), Taiwan

Transcription

1 Program & Abstract

2 Overview The 18th Taiwan-Japan-Korea Symposium on Strongly Correlated Electron Systems (TJK18) will be held at the Caesar Park Hotel, Kenting, Taiwan on the 22-23, February This series of symposia started originally as a workshop on recent advances in the study of strongly correlated materials in Korea and Japan, and evolved into the Korea-Japan-Taiwan Symposium when Taiwan held the 6th meeting in The symposium has become an annual tradition and continues to be an important meeting to promote communication and collaboration among Asian countries and for advancing research activities in the field of strongly correlated materials. Organizers : National Synchrotron Radiation Research Center (NSRRC), Taiwan National Chiao-Tung University (NCTU), Taiwan Sponsors : Ministry of Science and Technology, Taiwan National Synchrotron Radiation Research Center, Taiwan Institute of Physics, Academia Sinica, Taiwan

3 Scope The symposium will cover novel materials and properties of strongly correlated electron systems, including but not limited to the following subjects: Novel spectroscopy, Exotic superconductors, Surfaces and Interfaces, Spin-orbit coupling, Frustrated magnetism, Multiferroics, etc. The symposium will also include presentations and discussions about state-of-theart spectroscopic techniques which contribute to the understanding of the above materials (e.g., time-resolved photoemission, soft x-ray magnetic circular dichroism, x-ray magnetic resonant scattering). International Committees Atsushi Fujimori ( University of Tokyo, Japan ) Tsuyoshi Kimura ( University of Tokyo, Japan ) Jaejun Yu ( Seoul National University, Korea ) Je-Geun Park ( Seoul National University, Korea ) Di-Jing Huang ( National Synchrotron Radiation Research Center, Taiwan ) Ying-Hao Chu ( National Chiao Tung University, Taiwan ) Local Organizing Committee Ashish Chainani : Co:chair (National Synchrotron Radiation Research Center ) Cheng-Maw Cheng : Co-chair(National Synchrotron Radiation Research Center ) Yen-Yi Chu ( National Synchrotron Radiation Research Center ) Ying-Hao Chu ( National Chiao Tung University ) Chao-Hung Du ( Tamkang University ) Guang-yu Guo ( National Taiwan University ) Hung-Wei Shiu ( National Synchrotron Radiation Research Center ) Di-Jing Huang ( National Synchrotron Radiation Research Center ) Hsiao-Yu Huang ( National Synchrotron Radiation Research Center ) Ching-Shun Ku ( National Synchrotron Radiation Research Center ) Ping-Hui Lin ( National Synchrotron Radiation Research Center ) Way-Fong Pong ( Tamkang University ) Jun Okamoto ( National Synchrotron Radiation Research Center ) Jan-Chi Yang ( National Cheng Kung University )

4 Time Table The 18th Taiwan-Japan-Korea Symposium on Strongly Correlated Electron Systems 22th February, 2018 (Thursday) 8:30~9:00 Registration 9:00~9:15 Opening Remarks 9:15~12:00 Session (I) 12:00~13:30 Lunch 13:30~17:50 Session (II) 18:30~ Banquet 23th February, 2018 (Friday) 8:30~11:00 Session (III) 11:15~12:00 Poster flash session 12:00~14:00 Lunch + Poster Session 14:00~16:00 Session (IV) 16:00~16:10 Poster Awards 16:10 Closing Remarks Note: Poster flash session /1~2 min. poster presentation

5 THE 18th TAIWAN-JAPAN-KOREA SYMPOSIUM ON STRONGLY CORRELATED ELECTRON SYSTEMS (TJK18) 22 February 2018 (Thursday) Session I 08:30 Rigistration 09:00 Opening Remarks Session Chair: Jaejun Yu 09:15 A1 Orbital moment anisotropy of magnetic thin films studied by angle-dependent XMCD Atsushi Fujimori, University of Tokyo, Japan 09:45 A2 Broken Symmetries, Non-reciprocity and Multiferroicity 10:15 Coffee break Sang-Wook Cheong, Rutgers University, USA Session Chair: Je-Geun Park 10:30 A3 Exploration for New Room-temperature Magnetoelectrics Tsuyoshi Kimura, University of Tokyo, Japan 11:00 A4 Realization of Chern Insulators in Layered Transition Metal Compounds Jaejun Yu, Seoul National University, Korea 11:30 A5 Topological Materials and Heterostructure 12:00 Lunch Tay-Rong Chang, National Cheng-Kung University, Taiwan Session II Session Chair : Atsushi Fujimori 13:30 B1 The c-axis Dimer and Its Electronic Break-up: the Insulator-to- Metal Transition in Ti2O3 L.H. Tjeng, Max Planck Institute, Dresden, Germany 14:00 B2 Charge ordering and thermoelectric properties in Hollandite Titanates Takuro Katsufuji, Wseda University, Japan 14:30 B3 Soft X-ray ptychography imaging at TPS Hung Wei Shiu, NSRRC, Taiwan 14:45 B4 Excitonic Mott Insulator of LaCoO3 Investigated by Resonant Inelastic X-ray Scattering Hsiao-Yu Huang, NSRRC, Taiwan

6 15:00 Coffee break Session Chair : H. Takagi 15:20 B5 Anisotropy in the Thermal Hysteresis of Resistivity and Charge Density Wave Nature of Single Crystal SrFeO3-δ Way-Faung Pong, Tamkang University, Taiwan 15:50 B6 Phase Coherence and Functionality of Chiral Magnetism Yoshihiko Togawa, Osaka Prefecture University, Japan 16:20 B7 Spin Separation Due to An Inherent Spontaneous Symmetry Breaking of the Fractional Topological Insulator Kwon Park, KIAS, Korea 16:50 B8 Visualizing Topological Matters by Spectroscopic Imaging- Scanning Tunneling Microscope Tien-Ming Chuang, Academia Sinica, Taiwan 17:20 B9 Topological phase transition in black phosphorus Keun Su Kim, Yonsei University, Korea Banquet

7 23 February 2018 (Friday) Session III Session Chair: Ying-Hao Chu 09:00 C1 Exotic Spin-Orbital Entangled State in 4d and 5d Transition Metal Oxides beyond Jeff=1/2 Physics Hide Takagi, University of Tokyo, Japan 09:30 C2 Highly Anisotropic Magnetoresistance in an Antiferromagnetic Iridate Sr2IrO4 Younjung Jo, Kyungpook National University, Korea 10:00 C3 Relation between the Co-O Bond Lengths and the Spin State of Co in Layered Cobaltates: Jin-Ming Chen, NSRRC, Taiwan a High-Pressure Study 10:30 C4 Magnetic van der Waals Materials TMPS3, a New Platform for 11:00 Coffee break SCES Physics on Two-dimension Je-Geun Park, Seoul National University, Korea 11:15 Poster flash session (Session Chair : T. Kimura) 12:00 Lunch + Poster Session Session IV Session Chair: Way-Faung Pong 14:00 D1 High resolution laser-arpes on topological superconductor Shik Shin, University of Tokyo, Japan 14:30 D2 Band Structure Engineering : Heterostructure Comprised of 2D group V elements and Topological Insulators Cheng-Maw Cheng, NSRRC, Taiwan 15:00 D3 Blackswan metal Jeehoon Kim, POSTECH, Korea 15:30 D4 Microstructural Imaging by Using Scanning Laue Nanodiffraction at Taiwan Photon Source Ching-Shun Ku, NSRRC, Taiwan 15:45 D5 Anisotropic spin-flip-induced multiferroic behavior in kagome Cu3Bi(SeO3)2O2Cl Hung-Cheng Wu, National Sun Yat-Sen University, Taiwan 16:00 Poster Awards 16:10 Closing Remarks (Session Chair : Di-Jing Huang)

8 Poster Session Poster Presenters P1 Soonmin Kang (Seoul National University, Korea) RIXS studies of Metal-Insulator Transition with Concomitant Quantum Confinement Effect in SrRuO 3 Thin films P2 D. W. Shin (POSTECH, Korea) Violation of Ohm s law in Weyl metal P3 Ping-Chun Wu (NCTU,Taiwan) High Mobility Two-Dimensional Electron Gases at Non-Polar Interfaces P4 Chun-Hao Ma (NCTU,Taiwan) Transparent Anti-Radiation Ferroelectric Memory Based on Flexible Oxide Heteroepitaxy P5 Min Yen (NCTU, Taiwan) The Study of La 0.7Sr 0.3MnO 3/Muscovite Heteroepitaxial Structure P6 J. Okamoto (NSRRC, Taiwan) P7 P8 P9 P10 P11 P12 P13 XAS and RIXS study of the electronic structure of DyFe 3(BO 4) 3 Myeong jun Oh (Kyungpook National University, Korea) Fabrication of Localized Superconducting BaFe 2As 2 Films using Cobalt-ion implantation Y.H. Juan (NCTU, Taiwan) Growth of Yttria Stabilized Zirconia on Flexible Muscovite Substrate by van der Waals Epitaxy Pei-Chun Wang (NCTU, Taiwan) SrTiO 3/ZnO Heterostructure for Transparent and Flexible Water Splitting Photoelectrode Yu-Hong Lai (NCTU, Taiwan) Revolutionary Thin Film with Transitional Composition S. Suetsugu (The University of Tokyo, Japan) Three-dimensional massive Dirac electrons in Sr 3PbO antiperovskite Meng-Fu Tsai (NCTU, Taiwan) Flexible Nonvolatile Transistor based on Aluminum-doped ZnO/ Pb(Zr 0.7Ti 0.3)O 3 Heteroepitaxial Structure Y. Hayashi (The University of Tokyo, Japan) High-pressure phase diagram by NMR and magnetization study on hyperhoneycomb β-li 2IrO 3

9 P14 P15 P16 P17 P18 P19 P20 P21 P22 P23 P24 P25 P26 P27 Chien-Ming Tu (Lund Univ. Sweden) Helicity-Dependent THz Emission from Topological Insulator Sb 2Te 3 K. Kitagawa (The University of Tokyo, Japan) Quantum Liquid of Honeycomb Iridate Yoshinobu Nakamura (The University of Tokyo, Japan) Hydrogen Insertion in Anti-perovskite Nitrides, Mn 3CuN and Ca 3BiN M. Negishi (The University of Tokyo, Japan) Phase control of Dirac node electrons in perovskite-type AIr 1-xSn xo 3 thin films (A = Sr, Ca) Sungmo Kang (Seoul National University, Korea) Quantum Anomalous Hall Effect with Higher Chern Numbers in Electron-Doped CrSiTe 3: A First-Principles Prediction Deng-Li Ko (NCTU, Taiwan) Mechanically Tunable Nonlinear Dielectrics Pao-Wen Shao (NCTU) Domain Switching Kinetics and Relaxation of Transparent and Flexible Ferroelectric Heterostructures K. Ikeda (The University of Tokyo, Japan) Magnetic field angle-dependent XMCD study of L 10-ordered FePt thin films with perpendicular magnetic anisotropy C.Y. Yang (NCTU, Taiwan) Transparent (Ba,La)SnO 3/Muscovite Heteroepitaxy for Flexible Optoelectronics and Thermoelectric Yu-Hui Liang (TKU, Taiwan) Study of the Magnetic Structure of Single Crystal YBaCuFeO 5 Using Inelastic Neutron Scattering Yu-Hao Tu (NCTU, Taiwan) Ferroelectric Properties of Epitaxial Bismuth Ferrite Thin Film on Flexible Muscovite Substrate Seungjin Kang (Seoul National University, Korea) Two-Dimensional Metal-Organic Framework Kagome Lattice with Non-Trivial Topological Band Structure Tomomasa Kajita (Waseda University, Japan) Dynamics of phase transitions in the orbital-ordered vanadates Kazuma Funahashi (Waseda University, Japan) Magnetotransport properties of Ba 1-xSr xv 13O 18 P28 Hao-Hsiang Jia (NTHU, Taiwan )

10 P29 P30 P31 P32 P33 P34 P35 P36 P37 P38 P39 P40 P41 Time-Resolved Angle-resolved Photoemission Spectroscopy by Using Femtosecond High Harmonic Generation Sae Hee Ryu (Yonsei University, Korea) Electronic structure of single-crystalline black phosphorus Chun-Hao Lai (TKU, Taiwan) Neutron Powder Diffraction Study of the Double Perovskite Oxides YBa(Cu 1-xFe x) 2O 5 G. Shibata (University of Tokyo, Japan) Magnetically-induced anisotropic charge distribution in La 1-xSr xmno 3 thin films revealed by x-ray magnetic linear dichroism Yi-De Liou (NCKU, Taiwan) Giant Photostriction in Perovskite SrIrO 3 Thin Films Yuan-Chih Wu (NCKU, Taiwan) Optical control of ferroelectricity in multiferroic thin films Marian Blankenhorn (University of Stuttgart, Germany) Magnetic semimetallic state in pyrochlore ruthenate Cd 2Ru 2O 7 Min Jae Huh (Yonsei University, Korea) Modulating the band structure of black phosphorus via surface doping P.C. Chiang (NCTU, Taiwan) Experimental Control of the structure in SrCuO 2 ultrathin films Ting-Chun Huang(NSRRC&NCTU, Taiwan) Epitaxial Growth and RIXS Study of Strained LaCoO 3 Thin Films on LSAT(111) Yen-Yi Chu (NSRRC, Taiwan) Soft X-ray Bragg CDI at TPS Mohammad Pakdaman (MPI, Germany) Magnetotransport and Quantum Oscillations Phenomena in Dirac Semimetal Na 3Bi Qingyu He (MPI, Germany) Spectroscopic-Imaging STM of Dirac line node Materials Xinglu Que (MPI, Germany) Spectroscopic imaging STM study on an excitonic insulator Ta 2NiSe 5

11 A1 Orbital anisotropies of magnetic thin films studied by angledependent XMCD A. Fujimori Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo , Japan Magnetic anisotropy is one of the most important properties of ferromagnetic materials, and its microscopic origin has been the subject of intensive research. So far, magnetic anisotropy energy (MAE) has usually been considered proportional to the orbital magnetic moment anisotropy (OMA) as proposed by Bruno [1], but it has also been pointed out that additional contributions to MAE from the magnetic dipole MT, i.e., the anisotropic spatial distribution of spin-polarized electrons, become important when spin-orbit coupling (SOC) is not negligible [2]. In order to investigate the microscopic origin of MAE, we have carried out angle-dependent x-ray magnetic circular dichroism (AD-XMCD) experiment on ferromagnetic thin films of La1-xSrxMnO3 (LSMO) [3] and L10-ordered FePt [4]. In LSMO, the OMA of Mn 3d electrons was small but MT was substantial and changed its sign depending on the epitaxial strain from the substrate, leading to straindependent MAE and MT. As for L10-FePt, Fe 3d and Pt 5d electrons were shown to have opposite OMA. Although the Fe 3d OMA was apparently consistent with Bruno s relationship, considering the first-principles calculation that the MAE of L10- FePt is governed by that of Pt 5d electrons rather than Fe 3d electrons [5], we concluded that Bruno s relationship was violated for Pt 5d, which can be understood as due to the strong SOC of Pt 5d electrons. Also, AD-XMCD indicated a finite MT for the Fe 3d electrons. This work has been done in collaboration with G. Shibata, K. Ikeda, Y. Nonaka, Z. Chi, M. Kitamura, H. Kumigashira, M. Minohara, T. Koide, K. Amemiya, M. Sakamaki, K. Takanashi, T. Seki, M. Suzuki, N. Kawamura, and A. Tanaka. [1] P. Bruno, Phys. Rev. B 39, 865 (1989). [2] G. van der Laan, J. Phys.: Condens. Matter 10, 3239 (1998). [3] G. Shibata et al., to appear in npj Quantum Mater. [4] K. Ikeda et al., Appl. Phys. Lett. 111, (2017). [5] I. V. Solovyev et al., P. H. Dederichs, and I. Mertig, Phys. Rev. B 52, (1995).

12 A2 Broken Symmetries, Non-reciprocity and Multiferroicity S-W. Cheong Rutgers Center for Emergent Materials The interplay of space and time symmetries, ferroic properties, chirality and notions of reciprocity determines many of the technologically important properties of materials such as optical diode effect, e.g. in polar ferromagnet FeZnMo3O8. We illustrate these concepts including non-reciprocal directional dichroism through a number of practical examples. In particular, the conditions for non-reciprocity of ferro-rotational order are discussed and the possible use of linear optical gyration is suggested as a way to detect ferro-rotational domains. Finally, we provide means to achieve high-temperature optical diode effect and elucidate multiferroic behaviors as a result of helical versus cycloidal spins.

13 A3 Exploration for New Room-temperature Magnetoelectrics H. Ueda, 1 T. Akita, 2 Y. Uchida, 2 and T. Kimura 3 1 Division of Materials Physics, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka, , Japan. 2 Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka, , Japan. 3 Department of Advanced Materials Science, University of Tokyo, Kashiwa, Chiba, , Japan. In the past fifteen years, materials showing the coupling phenomena between magnetism and (ferro)electricity, i.e., magnetoelectric effect, have attracted a great deal of attention including practical point of views, and a number of new magnetoelectrics and multiferroics have been reported. However, most of the materials studied to date can be magnetoelectric only far below room temperature, which has hampered our practical use of them. Thus, the exploration for room-temperature magnetoelectrics is still a challenging topic in applied physics and materials science. In this presentation, we propose a new strategy to achieve room-temperature magnetoelectrics. Almost all the magnetoelectrics reported so far contain magnetic metal ions (or radicals), which are essential for magnetic control of (ferro)electric property. However, we focused on a completely different material from the conventional magnetoelectrics; a new magnetoelectric material is liquid crystal free from magnetic metal ions. We show our success in magnetic control of ferroelectric polarization at room temperature in a chiral smectic liquid crystal. [1] H. Ueda et al., Appl. Phys. Lett. 111, (2017).

14 A4 Realization of Chern Insulators in Layered Transition Metal Compounds Jaejun Yu * Center for Theoretical Physics, Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea A Chern insulator is a new topological state of matter exhibiting a nonzero quantized Hall conductivity without an external magnetic field corresponding to the quantum anomalous Hall effect. The experimental realizations of Chern insulators have been devoted to magnetically doped topological-insulator thin films but demonstrated the effect at low temperatures due to small band gaps. While the nontrivial band topology arising from band inversions driven by spin-orbit coupling is responsible for the quantum spin Hall effect, i.e., topological insulators, the broken time-reversal symmetry is required in addition to the nontrivial band topology. Recently, we have discovered that a metal-organic framework, transition-metal chalcogenide, and transition-metal halide compounds belong to a family of two-dimensional layered compounds exhibiting the characteristics of Chern insulators. By carrying out first-principles density-functional-theory calculations, we demonstrate that each compound becomes a ferromagnetic insulator with a non-trivial Chern number. All the proposed compounds consist of either Kagome or honeycomb lattices of transition metal atoms. While transition metal atoms are responsible for the ferromagnetic ground state, the band topology depends on the hopping matrix elements through chalcogen and halogen atoms. The nontrivial band topology is confirmed to have a nonzero Chern number, quantized Hall conductivity, and chiral edge states by using the Wannier function analysis. Further prospects of Chern insulator materials will be discussed. * Work done in collaboration with Santu Baidya (CCES-IBS), Seungjin Kang (SNU), Sung Mo Kang (SNU), and Choong H. Kim (CCES-IBS) and supported by the National Research Foundation of Korea (no. 2017R1A2B ).

15 A5 Topological Materials and Heterostructure Tay-Rong Chang 1, Horng-Tay Jeng 2,3, Hsin Lin 3, and M. Z. Hasan 4 1 Department of Physics, National Cheng Kung University, Tainan 701, Taiwan 2 Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan 3 Institute of Physics, Academia Sinica, Taipei 11529, Taiwan 4 Department of Physics, Princeton University, Princeton, New Jersey 08544, USA The topological insulator (TI) is a newly discovered phase in condensed matter systems. The TI is featured by a bulk energy gap originating from spin-orbit coupling and time-reversal symmetry protected gapless surface states, which is distinct from the conventional band insulator. Recently the topological classification has been extended beyond insulators; part of the research interest in topological phenomena in condensed matter has been moved from insulator to semimetals, leading to a new topological phase, topological semimetals (TSMs). Topological semimetal is the three-dimensional analogy of graphene in which the bulk band shows a linear dispersion relation from the nodal point in all three momentum directions, or displays one-dimensional nodal-loop in Brillouin zone. In this talk, I will briefly introduce the key concepts of topology in condensed matter physics and then show our recent predications on TSMs, Dirac semimetals [1], Weyl semimetals [2], nodal-line semimetals [3,4], and superconducting topological insulator [5]. Besides three-dimensional systems, the electronic structures of metal/ti heterostructure [6,7] will also be discussed in this talk. [1] T.-R. Chang, et al, Phys. Rev. Lett. 119, (2017). [2] T.-R. Chang, et al, Nat. Commun. 7, (2016). [3] G. Bian, T.-R. Chang*, R. Sankar, et al, Nat. Commun. 7, (2016). [4] G. Bian, T.-R. Chang*, H. Zheng, et al, Phys. Rev. B 93,121113(R) (2016). [5] T.-R. Chang, et al, Phys. Rev. B 93, (2016). [6] C.-H. Chang, T.-R. Chang*, and H.-T. Jeng, NPG Asia Materials 8, e332 (2016). [7] S. H. Su, et al, Chemistry of Materials 29, 8992 (2017).

16 B1 The c-axis dimer and its electronic break-up: the insulator-to-metal transition in Ti2O3 C. F. Chang, T. C. Koethe, Z. Hu, J. Weinen, S. Agrestini, J. Gegner, H. Ott, G. Panaccione, Hua Wu, M. W. Haverkort, H. Roth, A. C. Komarek, F. Offi,G. Monaco, Y.-F. Liao, K.-D. Tsuei, H. -J. Lin, C. T. Chen, A. Tanaka, and L. H. Tjeng We report on our investigation of the electronic structure of Ti2O3 using (hard) x- ray photoelectron and soft x-ray absorption spectroscopy. From the distinct satellite structures in the spectra we have been able to establish unambiguously that the Ti-Ti c- axis dimer in the corundum crystal structure is electronically present and forms an a1ga1g molecular singlet in the low temperature insulating phase. Upon heating we observed a considerable spectral weight transfer to lower energies with orbital reconstruction. The insulator-metal transition may be viewed as a transition from a solid of isolated Ti-Ti molecules into a solid of electronically partially broken dimers where the Ti ions acquire additional hopping in the a-b plane via the e_g channel, the opening of which requires the consideration of the multiplet structure of the on-site Coulomb interaction.

17 B2 Charge ordering and thermoelectric properties in hollandite titanates T. Katsufuji Department of Physics, Waseda University, Tokyo , Japan Hollandite structure with the chemical formula of A2B8C16 contains double chains of edge-sharing BC6 octahedra along the c axis of a tetragonal structure, and a one-dimensional conduction along the c axis is expected. We have found that hollandite titanates BaxTi8O16+, where n (0.1 n 0.4) electrons exist per Ti, exhibit a charge ordering at ~200 K along the c axis, and various physical properties show anomalies with this charge ordering. We also found that this series of compounds exhibit large Seebeck coefficients, which is caused by the degeneracy of the d states, and a small phonon thermal conductivity, which is caused by the fluctuation of the charge/orbital degrees of freedom of Ti d electrons, and thus can be good thermoelectric materials above the transition temperature. [1] R Murata et al., Phys. Rev. B 92, (R) (2015). [2] T. Katsufuji et al, J. Phys. Soc. Jpn. 85, (2016).

18 B3 Soft X-ray ptychography imaging at TPS Hung Wei Shiu 1 National Synchrotron Radiation Research Center, Hsinchu Taiwan Soft X-ray spectromicroscopy is a powerful tool which can provide 2D or 3D imaging with chemical, electronic and structural information at the nanoscale. Scanning transmission X-ray microscopy (STXM) is one of the most useful and productive of all synchrotron based microscopes in a broad range of sample systems. It is particularly powerful for the radiation sensitive soft materials compared with the other soft X-ray microscopies. The spatial resolution was limited by the zone plate lens. In order to improve the spatial resolution, a coherent diffraction imaging (CDI) based technique named Ptychography is developed. It is done by scanning a sample through a coherent X-ray spot created by KirkPartrick- Baes (KB) optics, pinhole or zone plates with overlapping steps and the scattered pattern was collected on a CCD camera. With suitable iterative algorithm, the phase and amplitude of the object can be reconstructed. A spatial resolution below 4 nm was achieved in the soft X-ray region. The CDI branch line at TPS41A is a multi-purpose beamline which can measure the soft X-ray diffraction, Bragg CDI and ptychography through the combination of scanning system and diffractormeter. The beamline was designed to deliver high coherent flux in the energy range from 400 ev to 1200 ev. The presentation will discuss the design, expectation, current status and recent commissioning results for the CDI branch line at TPS 41A.

19 B4 Excitonic Mott Insulator of LaCoO3 Investigated by Resonant Inelastic X-ray Scattering H.-Y. Huang 1, T.-C. Huang 2, J. Okamoto 1, A. Singh 1, S. Ishihara 3, Y.-H. Chu 4, J. Chang 1, J.-H. Lee 5, A. Chainani 1, C.-T. Chen 1, D.-J. Huang 1 1 National Synchrotron Radiation Research Center, Hsinchu 30010, Taiwan 2 Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan 3 Department of Physics, Tohoku University, Sendai , Japan 4 Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan 5 Department of Physics, National Tsing Hua University, Hsinchu 30071, Taiwan The attractive Coulomb interactions between electrons in the conduction band and holes in the valence band in a semiconductor or semimetals can form an excitonic insulating (EI) state. Excitonic condensation has been proposed theoretically for long time. However, the EI phase has been hardly provided experimentally. Recently theoretical and experimental works have shown that excitonic insulators of correlated-electron materials can be realized in cobalt oxide. In this talk, we will present measurements of high-resolution resonant inelastic X-ray scattering (RIXS) at Co L-edge on LaCoO3 thin films grown on LSAT substrates. Instead of a low-spin (LS) state phase, the LaCoO3 film with a tensile strain exhibits an EI phase which is a quantum-mechanical superposition of a high-spin (HS) and intermediate-spin of Co 3+. RIXS results indicate that such an EI phase is dominated by a HS character, suggesting the EI phase is derived from the HS Mott insulator rather than a LS band insulator.

20 B5 Anisotropy in the thermal hysteresis of resistivity and charge density wave nature of single crystal SrFeO3-δ W. F. Pong Department of Physics, Tamkang University, Tamsui 251, Taiwan The local electronic and atomic structures of the high-quality single crystal of SrFeO3-δ (δ~0.19) were studied using temperature-dependent x-ray absorption and valence-band photoemission spectroscopy (VB-PES) to investigate the origin of anisotropic resistivity in the ab-plane and along the c-axis close to the region of thermal hysteresis (near Néel temperature, TN~78 K). All experiments herein were conducted during warming and cooling processes. The Fe L3,2-edge X-ray linear dichrois results show that during cooling from room temperature to below the transition temperature, the unoccupied Fe 3d eg states remain in persistently out-of-plane 3d3z 2 -r 2 orbitals. In contrast, in the warming process below the transition temperature, they change from 3d3z 2 -r 2 to in-plane 3dx 2 -y 2 orbitals. The nearest-neighbor (NN) Fe-O bond lengths also exhibit anisotropic behavior in the ab-plane and along the c-axis below TN. The anisotropic NN Fe-O bond lengths and Debye-Waller factors stabilize the in-plane Fe 3dx 2 -y 2 and out-of-plane 3d3z 2 -r 2 orbitals during warming and cooling, respectively. Additionally, a VB-PES study further confirms that a relative band gap opens at low temperature in both the ab-plane and along the c-axis, providing the clear evidence of the charge-density-wave nature of SrFeO3-δ (δ~ 0.19) single crystal.

21 B6 Phase Coherence and Functionality of Chiral Magnetism Yoshihiko Togawa 1,2,3 1 Department of Physics and Electronics, Osaka Prefecture University, Sakai, Osaka JAPAN 2 Chirality Research Center, Hiroshima University Higashi-Hiroshima, , Japan 3 School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, U.K. Nontrivial spin order with magnetic chirality emerges in a particular class of magnetic materials with structural chirality, frequently referred to as chiral magnetic materials. They exhibit many kinds of emergent physical properties through the coupling of chiral magnetic order with conduction electrons and electromagnetic fields. One promising candidate for achieving these couplings is a chiral spin soliton lattice. In this talk, I will present recent experimental observations mainly carried out on the monoaxial chiral magnetic crystal CrNb3S6 [3-7], together with the underlying theoretical backgrounds [2]. The experiments were performed by means of magnetic imaging using electron beams as well as transport, magnetization, and resonance measurements. The chiral soliton lattice appears under a magnetic field perpendicular to the helical axis and is very robust and stable with phase coherence on a macroscopic length scale. The tunable and topological nature of the chiral soliton lattice gives rise to nontrivial physical properties. Indeed, it is demonstrated that many physical responses such as the interlayer magnetoresistance and magnetic resonance frequency scales to the soliton density, which plays an essential role as an order parameter in the chiral soliton lattice formation, and becomes quantized with the reduction of the system size. These interesting features arise from macroscopic phase coherence unique to the chiral soliton lattice and will lead to the exploration of routes to a new paradigm for applications in spin electronics using spin phase coherence. [1] For a review, Y. Togawa et al., J. Phys. Soc. Jpn. 85, (2016). [2] J. Kishine and A. S. Ovchinnikov, Solid State Physics 66, 1 (2015). [3] Y. Togawa et al., Phys. Rev. Lett. 108, (2012). [4] Y. Togawa et al., Phys. Rev. Lett. 111, (2013). [5] Y. Togawa et al., Phys. Rev. B 92, (R) (2015). [6] F. Goncalves et al., Phys. Rev. B 95, (2017). [7] J. Yonemura et al., Phys. Rev. B 96, (2017).

22 B7 Spin separation due to an inherent spontaneous symmetry breaking of the fractional topological insulator Kwon Park Korea Institute for Advanced Study Motivated by the close analogy with the fractional quantum Hall states (FQHSs), fractional Chern insulators (FCIs) are envisioned as strongly correlated, incompressible states emerging in a fractionally filled, (nearly) flat band with non-trivial Chern number. Built upon this vision, fractional topological insulators (FTIs) have been proposed as being composed of two independent copies of the FCI with opposite Chern numbers for different spins, preserving the time-reversal symmetry as a whole. An important question is if the correlation between electrons with different spins can be really ignored. To address this question, we investigate the effects of correlation in the presence of spin-dependent holomorphicity, i.e., electrons of one spin species reside in the holomorphic lowest Landau level, while those of the other in the antiholomorphic counterpart. By constructing and performing exact diagonalization of an appropriate model Hamiltonian, here, we show that generic, strongly correlated, fractionally filled states with spin-dependent holomorphicity cannot be described as two independent copies of the FQHS, suggesting that FTIs in the lattice cannot be described as those of the FCI either. Fractionally filled states in this system are generally compressible except at half filling, where an insulating state called the half-filled spin-holomorphic FTI occurs. It is predicted that the half-filled spin-holomorphic FTI is susceptible to an inherent spontaneous symmetry breaking, leading to the spatial separation of spins.

23 B8 Visualizing Topological Matters by Spectroscopic Imaging- Scanning Tunneling Microscope Tien-Ming Chuang Institute of Physics, Academia Sinica, Taipei 11529, Taiwan Topological materials, which exhibit novel spin structure and non-trivial topology in band structure in the make them the great platform to exhibit emergent phenomena and to engineer exotic quasiparticles. In this talk, I will discuss our recent results on two unique materials. First, I will present topological properties in noncentrosymmetric superconductor, PbTaSe2. Using quasiparticle scattering interference imaging with the support of DFT calculation, we found the topological surface states (TSSs) cross Fermi level on the Pb-terminated surface of PbTaSe2. Furthermore, the TSSs open a full superconducting gap at the bulk Tc and a zero bias conductance peak is observed in the vortex core, indicating PbTaSe2 is a promising topological superconductor candidate [1]. Second, I will report our study on a Dirac line node semimetal ZrSiS. Our measurements revealed the signatures of the Dirac surface and bulk bands with linear dispersion up to several hundred mev. We also identified multiple Shubnikov de-haas frequencies from our magneto-transport measurements. The non-orbital magnetoresistance contribution yields nearly H-linear dependence, which is a common feature in many Dirac and Weyl semimetals. Our results show the unique Dirac line nodes phase in the ZrSiS family represents a unique system for exploring Dirac line node physics. [1] S.-Y. Guan et al., Science Advances 2, e (2016)

24 B9 Topological phase transition in black phosphorus Keun Su Kim 1 1 Department of Physics, Yonsei University, Seoul 03722, Republic of Korea Two-dimensional (2D) semiconductors, such as transition-metal dichalcogenides and black phosphorus, have emerged as a class of materials that may impact our future electronics technology. Modulating their band structures widely is important not only to systematically study their topological phase diagrams, but also to explore novel Dirac or Weyl semimetals. In this talk, I will introduce our recent angle-resolved photoemission spectroscopy (ARPES) studies on the tunable band gap and topological phase transition in black phosphorus. The in-situ deposition of alkali-metal atoms on the surface of black phosphorus produces strong vertical electric field and modulate its bandgap by the giant Stark effect [1]. We found that this tunable band gap can be exploited to artificially induce the topological phase transition from a trivial insulator to a Dirac semimetal with a pair of Dirac points [2]. Unlike graphene, the Dirac point of black phosphorus is stable even in the presence of spin-orbit coupling, as protected by space-time inversion symmetry [2]. At the critical point, it shows an unusual spectrum, whose dispersion is highly anisotropic, linear in armchair and quadratic in zigzag directions [1]. [1] J. Kim et al., Science 349, 723 (2015). [2] J. Kim et al., Phys. Rev. Lett. 119, (2017).

25 C2 Highly Anisotropic Magnetoresistance in an Antiferromagnetic Iridate Sr2IrO4 Nara Lee 1, Eunjung Ko 1, Woun Kang 2, Hyoung Joon Choi 1, Young Jai Choi 1, Younjung Jo 3. 1 Department of Physics, Yonsei University, Seoul 03722, Korea 2 Department of Physics, Ewha Womans University, Seoul 03760, Korea, 3 Department of Physics, Kyungpook National University, Daegu 41566, Korea The novel electronic state of the canted antiferromagnetic insulator Sr2IrO4 has been well described by the spin-orbit-entangled isospin Jeff=1/2, suggesting the prospect for a wide range of emergent phenomena and exotic functionalities. However, the role of isospin in transport phenomena is not well recognized. We demonstrate antiferromagnet-based spintronic functionality by combining unique characteristics of the isospin state in Sr2IrO4. Our work establishes a link between isospins and magnetotransport in a strongly spin-orbit-coupled Sr2IrO4. The peculiar anisotropic magnetoresistance effect provides a beneficial foundation for fundamental and applied research on antiferromagnetic spintronics. References 1. N. P. Author1, Phys. Rev. A 70, (2004). 2. N. P. Author1 and N.P. Author2, e-print arxiv: (2005). 3. N. P. Author1 and N. P. Author2, Book Title (Publisher, City, 2007). 4.N. P. Author1, Proc. of 3 rd International Conference on Superconductivity and Magnetism-ICSM2012, edited by N. P. Editor1 (Publisher, City, 2013), p. 120.

26 C3 Relation between the Co-O bond lengths and the spin state of Co in layered Cobaltates: a high-pressure study Yi-Ying Chin 1, Hong-Ji Lin 1, Zhiwei Hu 2, Chang-Yang Kuo 2, Daria Mikhailova 2,3,4, Jenn-Min Lee 1, Shu-Chih Haw 1, Shin-An Chen 1, Walter Schnelle 2, Hirofumi Ishii 1, Nozomu Hiraoka 1, Yen-Fa Liao 1, Ku-Ding Tsuei 1, Arata Tanaka 5, Liu Hao Tjeng 2, Chien-Te Chen 1, and Jin-Ming Chen 1 1 National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan 2 Max Planck Institute for Chemical Physics of Solids, Dresden, D-01187, Germany 3 Karlsruhe Institute of Technology (KIT), Institute for Applied Materials (IAM), Eggenstein-Leopoldshafen, D-76344, Germany 4 Institute for Complex Materials, IFW Dresden, Dresden, D-01069, Germany 5 Department of Quantum Matter, ADSM, Hiroshima University, Higashi-Hiroshima, , Japan The pressure-response of the Co-O bond lengths and the spin state of Co ions in a hybrid 3d-5d solid-state oxide Sr2Co0.5Ir0.5O4 with a layered K2NiF4-type structure was studied by using hard X-ray absorption and emission spectroscopies. The Co-K and the Ir-L3 X-ray absorption spectra demonstrate that the Ir 5+ and the Co 3+ valence states at ambient conditions are not affected by pressure. The Co Kβ emission spectra, on the other hand, revealed a gradual spin state transition of Co 3+ ions from a high-spin (S = 2) state at ambient pressure to a complete low-spin state (S = 0) at 40 GPa without crossing the intermediate spin state (S =1). This can be well understood from our calculated phase diagram in which we consider the energies of the low spin, intermediate spin and high spin states of Co 3+ ions as a function of the anisotropic distortion of the octahedral local coordination in the layered oxide. We infer that a short in-plane Co-O bond length (< 1.90 Å ) as well as a very large ratio of Co-Oapex/Co-Oin-plane is needed to stabilize the IS Co 3+, a situation which is rarely met in reality.

27 C4 Magnetic van der Waals materials TMPS3, a new platform for SCES physics on two-dimension Je-Geun Park 1,2 1 Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Korea 2 Department of Physics & Astronomy, Seoul National University, Seoul 08826, Korea Two dimension (2D) has a very special place in the development of the whole physics, especially condensed matter physics. The importance of some 2D-related works have been recognized by several Nobel prizes awarded to the following subjects in 2D: IQHE in 1985, FQHE in 1998, and most recently topological physic in Therefore, it is nature to search for new 2D materials in the hope that it will lead to entirely new observations. When it comes to magnetism, we do not really have good Toy models in the true sense of Duncan Haldane [1]. Nearest we get is some of artificial thin films nowadays routinely grown by PLD techniques. But that s it! In this talk, I am going to show how some of naturally occurring so-called magnetic van der Waals materials can be used as a platform doing the exactly same thing. A big advantage of this material is that it is magnetic and so intrinsically strongly correlated [2]. By using one of such systems, i.e. TMPS3 with TM being occupied by transition metal elements, I will demonstrate how we can learn some of new correlation physics [3,4]. In the end, I will argue that this new class of materials can be used as a new platform for correlation physics on two dimension [5,6]. [1] F. Duncan M. Haldane, Rev. Mod. Phys. 89, (2017) [2] Je-Geun Park, J. Phys. Condens. Matter 28, (2016) [3] Cheng-Tai Kuo, et al., Scientific Reports 6, (2016) [4] Jae-Ung Lee, et al., Nano Lett, 16, 7433 (2016) [5] So Yeun Kim, et al., Phys. Rev. Lett. (submitted): arxiv: [6] Ki Hoon Lee, et al., Phys. Rev. Lett. (submitted): arxiv:

28 D1 High resolution laser-arpes on topological superconductor Shik Shin 1 1 Institute for Solid State Physics, The University of Tokyo, Kashiwa,Chiba , Japan address: shin@issp.u-tokyo.ac.jp I would like to talk on topological superconductivity on the surface of an iron-based superconductor and topological surface states in bismuth selenide on niobium by using ultrahigh-resolution angle-resolved photoemission spectroscopy(arpes). Most of the proposed topological superconductors are usually realized in difficult-tofabricate heterostructures at low temperatures. Here by using high-resolution spin-resolved and angle-resolved photoelectron spectroscopy, we find that the iron-based superconductor FeTe1- xsex (x = 0.45, superconducting transition temperature Tc = 14.5 K) hosts Dirac-cone type spinhelical surface states at Fermi level; the surface states exhibit an s-wave superconducting gap below Tc. Our study shows that the surface states of FeTe0.55Se0.45 are 2D topologically superconducting, providing a simple and possibly high temperature platform for realizing Majorana states. [1] A topological insulator film coupled to a simple isotropic s-wave superconductor substrate can foster helical pairing of the Dirac fermions associated with the topological surface states. Experimental realization of such a system is exceedingly difficult, but using a novel "flipchip" technique, we have prepared single-crystalline Bi2Se3 films with predetermined thicknesses in terms of quintuple layers (QLs) on top of Nb substrates fresh from in-situ cleavage. Our angleresolved photoemission spectroscopy (ARPES) measurements of the film surface disclose superconducting gaps and coherence peaks of similar magnitude for both the topological surface states and bulk states. The ARPES spectral map as a function of temperature and film thickness up to 10 QLs reveals key characteristics relevant to the mechanism of coupling between the topological surface states and the superconducting Nb substrate; the effective coupling length is found to be much larger than the decay length of the topological surface states.[2] [1] P. Zhang, K. Yaji, T. Hashimoto, Y. Ota, T. Kondo, K. Okazaki, Z. Wang, J. Wen, G. D. Gu, H. Ding, and S. Shin, Science (2018) in press, arxiv: [2] D. Flötotto, Y. Ota, Y. Bai, C. Zhang, K. Okazaki, A. Tsuzuki, T. Hashimoto, J. N. Eckstein, S. Shin, and T.-C. Chiang 1., unpublished

29 D2 Band Structure Engineering : Heterostructure Comprised of 2D group V elements and Topological Insulators Cheng-Maw Cheng 1,2, S. H. Su 3, Pei-Yu Chuang 3, Wei-Chuan Chen 1, Shih- Chang Weng 1, Ku-Ding Tsuei 1, Chao-Kuei Lee 2,4,, Shih-Hsun Yu 5, Mitch Ming-Chi Chou 5, Hung-Duen Yang 2, J.C.A. Huang 3, Tay-Rong Chang 3, Horng-Tay Jeng 6 1 National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan 2 Department of Physics, National Sun Yat-sen University, Kaohsiung 80424, Taiwan 3 Department of Physics, National Cheng Kung University, Taiwan 701, Taiwan 4 Department of Photonics, National Sun Yat-sen University, Kaohsiung 80424, Taiwan 5 Department of Materials and Optoelectronics Science, National Sun Yat-sen University, Kaohsiung 80424, Taiwan 6 Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan makalu@nsrrc.org.tw Abstract Two dimensional materials have demonstrated attractive properties for physical and technological applications since the discovery of graphene. In contrast to graphene as zero gap semiconductor, 2D single layer crystalline phase of group V elements with a buckled honeycomb structure, such as arsenene, bismuthene and antimonene, were predicted to exhibit a broad range of band gap and high mobilities in optoelectronic applications. Here we derive the electronic structure of the heterostructure comprised of Bi and Sb bilayer (BL) on the top of Bi2Te3 and Sb2Te3 topological insulators. With scanning tunneling microscopy (STM) and low energy electron diffraction (LEED), we confirmed that wellorder Bi and Sb BL thin films were successfully prepared on Bi2Te3 and Sb2Te3 substrate respectively. In Bi bilayer/bi2te3 system, a large Rashba splitting and charge transfer was observed by band mapping result, but not proposed in previous studies. In Sb bilayer/sb2te3 system, the strong hybridization between Sb bilayer and Sb2Te3 cause a newly emerged Dirac cone and is in agreement with the first-principle calculation. Our finding provides a potential system to fabricate future spintronic devices.

30 D3 Blackswan metal Jeehoon kim 1 1 Department of Physics, POSTEC, Pohang 37673, Korea In 1827, German scientist Georg Ohm published Ohm's law of constant electrical resistance in metals. Ohm's Law is one of the unbreakable rules of experience after its discovery. It was recently discovered that Ohm's law, which never seemed to be broken, was violated in BiSb alloys. The BiSb alloy shows the twisting energy band of the electron and becomes a Weyl metal in the absence of time reversal symmetry. When an electric field is applied in a certain direction, some of the electrons move in the direction of the electric field without resistance. The density of electrons flowing without resistance changes with the applied electric field. As a result, no current flows in proportion to the applied voltage. Therefore, the resistance changes according to the voltage, that is, the metal does not satisfy Ohm's law. In this talk, we will look closely at the meaning of Ohm's law and share information on the principles and applications of Ohm's law that breaks the law.

31 D4 Microstructural Imaging by Using Scanning Laue Nanodiffraction at Taiwan Photon Source Ching-Shun Ku National Synchrotron Radiation Research Center, Hsinchu, Taiwan. The X-ray Nanodiffraction Beamline (XND) is one of the phase-i projects for Taiwan Photon Source (TPS). The end-station called FORMOSA (FOcus x-ray for MicrOStructure Analysis) is dedicated to use the focusing white/mono-beam Laue diffraction for structural analysis. For instance, users could obtain the 2D and 3D distribution of crystal phases, orientation, residual strain, stress and dislocations for materials in a complex form without distorting the sample during measurement. The current spatial resolution is better than 80 x 80 nm at lateral direction and 50 nm for depth. Furthermore, this end-station also provided many complementary tools. Tetraprobe stages could deploy several scanning probes to collect optical, electrical, surface properties with tens of nanometer resolution of specimens; the x-ray fluorescence detector provides elemental information and the cryo-stage integrated with heater for temperature dependence experiments. Particularly, it is also the first time in synchrotron history to integrate an online scanning electron microscopy (SEM) as a navigator. With spatial resolution down to 4 nm, it is able to find out the interest region with tiny structure on samples and also arrange the position for different probes. This end-station can function either in vacuum or ambient environments depending on the user s demands. In summary, XND beamline and FORMOSA end-station will provide not only 2D/3D-XRD but also XRF, XAS, XEOL/CL, SPM and SEM information for diverse research programs. This talk will cover some results from 2D materials, quantum dots and ultra-thin films to demonstrate the capabilities of XND.

32 D5 Anisotropic spin-flip induced multiferroic behavior in kagome Cu3Bi(SeO3)2O2Cl H. C. Wu 1, K. D. Chandrasekhar 1, J. K. Yuan 1, J. R. Huang 2, J.-Y. Lin 2, H. Berger 3, and H. D. Yang 1 1 Department of Physics, National Sun Yat-Sen University, Kaohsiung, 804 Taiwan 2 Institute of Physics, National Chiao Tung University, Hsinchu 30010, Taiwan 3 Institute of Physics of Complex Matter, Ecole Polytechnique Federal de Lausanne, CH-1015 Lausanne, Switzerland Abstract Temperature and magnetic field dependent magnetization, specific heat, dielectric, magneto-dielectric, and ferroelectric properties were investigated on kagome single crystal Cu3Bi(SeO3)2O2Cl. Without magnetic field, an antiferromagnetic transition is clearly established at TN ~ 25.6 K. Above the critical field Hc ~ 0.8 T, a metamagnetic spin-flip transition from antiferromagnetic to ferrimagnetic order at T ~ TN is induced anisotropically only for H // c. Simultaneously, a ferroelectric behavior is observed below T ~ TN, then a corresponding type-ii multiferroics emerges above Hc. The key mechanism of the anisotropic spin-flip induced multiferroicity in Cu3Bi(SeO3)2O2Cl can be ascribed to the breaking of magnetic two-fold symmetry in the bc plane above Hc.

33 P1 RIXS studies of Metal-Insulator Transition with Concomitant Quantum Confinement Effect in SrRuO3 Thin films Soonmin Kang 1,2, Yi Tseng 3, Byungmin Sohn 1,2, Seokhwan Yun 1,2, Bongju Kim 1,2, Daniel McNally 3, Eugenio Paris 3, Tae Won Noh 1,2, Sumio Ishihara 4, Thorsten Schmitt 3, and Je-Geun Park 1,2 1 Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea 2 Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Korea 3 Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland 4 Department of Physics, Tohoku University, Sendai , Japan SrRuO3 is a well-known member of ruthenates with a ferromagnetic phase below Curie temperature at 165 K. Unlike other ferromagnetic materials, conductivity of bulk SrRuO3 is high enough to be used as an oxide electrode with a stable perovskite structure. At the same time, it is one of the rare itinerant ferromagnetic oxides, which has attracted significant interest in its own right. Interestingly, it is also known that the metallic phase of bulk SrRuO3 is close to the boundary between Fermi-liquid and non-fermi-liquid states. Another interesting point is that SrRuO3 thin films undergoes a metal-to-insulator phase transition as decreasing thickness. Thus, SrRuO3 thin films can be a fertile ground for exploring some of fundamental physics. In addition, LDA+U band calculations found that the Ru orbitals of SrRuO3 thin film may exhibit rather unusual quantum confinement effects (QCE) as reducing the thickness [1]. As the thickness of film gets thinner, the enhanced QCE may induce the distinctive charge dynamics for each t2g orbital with regard to its geometry and each Ru orbital should be hybridized with different type of O orbitals in different position. This orbital-selective hybridization seems to be a main driving force of the intriguing insulating phase found for very thin samples. The purpose of this study was twofold. First, we wanted to investigate the charge dynamics of the metal-insulator transition by measuring the RIXS signals as a function of thickness across the metal-insulator transition. Second, we wished to examine the proposed QCE by measuring the charge dynamics. For this we carried out O K-edge RIXS at ADRESS beamline of SLS, PSI. [1] Y. J. Chang et. al., Phys. Rev. Lett. 103, , 2009

34 P2 Violation of Ohm s law in Weyl metal D. W. Shin 1,2 and J. H. Kim 1,2 1 Department of Physics, Pohang University of Science and Technology (POSTECH) 2 BK21 Plus The Weyl metal is one of the topological non-trivial materials holding Weyl fermions which are massless and have a chirality. The Weyl metal has been described in terms of axion electromagnetism rather than in Maxwell electromagnetism and has peculiar properties such as chiral anomaly, the presence of magnetic monopole in the reciprocal lattice space and negative longitudinal magneto resistance(nlmr). In this presentation, by transportation experiment besides NLMR, we observed Ohm s law was broken in Bi1-xSbx (x=0.04) and carried experimental and theoretical analysis of the violation of Ohm s law [1] [1] D. W. Shin and Y. W. Lee et. al., Nat. Mater 16, (2017).

35 P3 High Mobility Two-Dimensional Electron Gases at Non-Polar Interfaces Ping-Chun Wu 1 and Ying-Hao Chu Department of Materials Science and Engineering, National Chiao Tung University 2 Department of Electrophysics, National Chiao Tung University 3 Department of Material and Chemical Research Laboratories, Industrial Technology Research Institute The discovery of two-dimensional electron gases (2DEGs) at the interface of LaAlO3/SrTiO3 (LAO/STO) heterostructure has advanced the opportunity for oxide electronics. So far, the creation of 2DEGs at oxide interface still remains a huge debate. There are three main mechanisms that have been proposed: electronic reconstruction due to the polar discontinuity, accumulation of oxygen vacancy, and intermixing at the interface. These theories have earned wide recognition but arguments still remain unsettled. In this work, we create 2DEGs at non-polar interfaces by depositing strontium zirconate (SrZrO3), calcium titante (CaTiO3) and STO on STO substrate. The electron mobilities of the samples are all over 20,000 cm 2 V -1 s -1 at 4 K. The XRD reciprocal space mapping has demonstrated that the films are under biaxial strain. X-ray photoemission spectroscopy is adopted to reveal the band structure at the interface. Scanning transmission electron microscopy and electron energy-loss spectroscopy are used to evidence the origin of the 2DEGs. This work has excluded the claim of electronic reconstruction from polar discontinuity by creating 2DEGs at non-polar interface. Further, the notion of intermixing is also inconsistent since 2DEGs have been observed at homoepitaxial STO/STO interface. This work advanced the pathway to explore the origin of 2DEGs at oxide interfaces.

36 P4 Transparent Anti-Radiation Ferroelectric Memory Based on Flexible Oxide Heteroepitaxy Chun-Hao Ma 1,2, Po-Wen Chiu 1,3, and Ying-Hao Chu 2,4,5* 1 Institute of Electronics Engineering, National Tsing Hua University, Hsinchu, Taiwan 2 Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan 3 Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan 4 Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan 5 Department of Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu 31040, Taiwan In the era of Internet of Things, the demand for flexible and transparent electronic devices has moved to the forefront of materials science research. However, the radiation damage to the key performance become a crucial issue for those transparent devices apply under radiative environment. Here, we present a promising technology for nonvolatile transparent flexible electronic devices based on ferroelectric oxides. A direct fabrication of epitaxial lead lanthanum zirconate titanate (PLZT) on transparent flexible mica substrate with top and bottom Indium Tin oxide (ITO) electrodes has been presented. These transparent flexible ferroelectric heterostructures not only retain their superior performance, thermal stability, reliability and mechanical durability, but also exhibit remarkably robust properties against to radiation exposure. Our study demonstrates an extraordinary concept to realize transparent flexible nonvolatile electronic devices for the design and development of the next-generation smart devices with potential application in electronics, automotive, aerospace, nuclear and military systems.

37 P5 The Study of La0.7Sr0.3MnO3/Muscovite Heteroepitaxial Structure Min Yen 1 1, 2, 3* and Ying-Hao Chu 1 Department of Materials Science and Engineering, National Chiao Tung University 2 Department of electrophysics, National Chiao Tung University 3 Department of Material and Chemical Research Laboratories, Industrial Technology Research Institute Flexible function attracts much attention on each research field in the last decade. Based on flexibility, we can directly apply elastic strain on the system and study the interaction which is induced by strain, unlike the way that we only can exert strain by the mismatch between film and hard substrate in the past. At the same time, La0.7Sr0.3MnO3(LSMO) a material with colossal magnetoresistance(cmr) property in perovskite structure is believed that CMR performance is tunable by strain. However, there was a limitation that we can't apply strain arbitrarily. In this study, we choose muscovite as a flexible substrate to deposit LSMO thin film and utilize the advantage of flexibility that we can easily observe the coupling between elastic strain and magnetoresistance. To achieve high quality LSMO thin film on flexible muscovite, we deposit by pulsed laser deposition process and then X-ray diffraction as well as high-resolution transmission electron microscopy will use to characterize the structures. Bending test is performed to demonstrate the tunability of functionalities by strain through bending. Magnetic and electrical measurements are performed using Superconducting Quantum Interference Device (SQUID) and Physical Properties Measurement System (PPMS) respectively. This system truly exhibits excellent magnetic and electrical properties with flexible characteristics and offers a pathway to fabricate flexible functional devices. Keywords: heteroepitaxy, La0.7Sr0.3MnO3, colossal magnetoresistance, pulsed laser deposition, muscovite * Corresponding author s yhc@nctu.edu.tw

38 P6 XAS and RIXS study of the electronic structure of DyFe3(BO4)3 J. Okamoto 1, A. Singh 1, H. Y. Huang 1, T. C. Huang 1, W. B. Wu 1, Y. Tanaka 2, T. Usui 3, T. Kimura 4, C. T. Chen 1, D. J. Huang 1 and A. Chainani 1 1 National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan 2 RIKEN SPring-8 Center, Sayo, Hyogo , Japan 3 Devision of Materials Physics, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka , Japan 4 Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba , Japan The rare-earth iron borate DyFe3(BO4)3 exhibits a first order structural transition at TS = 285 K from the R32 trigonal structure to the P3121 (or P3221) trigonal structure, followed by a transition to an antiferromagnetic phase below TN = 38 K. It exhibits a magnetoelectric effect and spin-flop behavior below TN [1]. Neutron diffraction studies have shown that the spins in the Fe sublattice align along c-axis below TS [2], while recent studies have shown a quadrupole helix chirality setting in below TS for the Dy and Fe sublattices [3,4]. In this work, we have measured linear dichroism X-ray absorption spectroscopy (LD-XAS) at the Fe L2,3-edges and Dy M4,5-edges to study the temperature-dependent changes in the electronic structure across TS and TN. Our LD-XAS results show clear changes across TN but negligible changes across TS in both Fe and Dy spectra. We have also measured Fe L3-edge resonant inelastic X-ray scattering (RIXS) across TS and TN to determine the dd-transitions and low energy excitations in DyFe3(BO4)3 and their temperature dependence. Based on many-body cluster model calculations, we discuss the electronic structure of DyFe3(BO4)3 in comparing with XAS and RIXS spectra. [1] Yu. F. Popov et al., JETP Letters 89, 345 (2009). [2] C. Ritter et al., J. Phys. Conf. Serie 340, (2012). [3] T. Usui et al., Nature Materials 13, 611 (2014). [4] H. Nakajima et al., Phys. Rev. B 93, (2016).

39 P7 Fabrication of Localized Superconducting BaFe2As2 Films using Cobalt-ion implantation Myeong jun Oh 1, Jongmin Lee 2, Woun Kang 3, Sanghan Lee 2 and Younjung Jo 1 1 Department of Physics, Kyungpook National University, Daegu 41566, South Korea 2 Material Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, South Korea 3 Department of Physics, Ewha Womans University, Seoul 03760, South Korea In order to achieve a breakthrough in superconducting films applications, it is necessary to create a superconducting phase at specific locations. In this study, for the first time, we report the electron doping of Fe-based superconducting films, using Co ion implantation into BaFe2As2 films, demonstrated using secondary ion mass spectrometry (SIMS) and electrical transport measurements. As the distribution of Co ions follows well the ordinary implanted ion distribution into silicon, tools that are widely used in semiconductor research can be employed here for analysis of localized superconducting phase. The Co-ion implantation into BaFe2As2 is similar to the heavy-ion implantation into silicon, hence similar phenomena such as the ion-channeling effect and the presence of a nuclear stopping region in the range of tens of kev are observed. The quality of the superconducting films was evaluated using resistance measurements. Our Co-implanted BaFe2As2 film simultaneously shows a spin density wave and optimally doped superconducting transitions. The coexistence of the two transitions indicates that the irradiated dopant ions do not affect the entire film, but only up to a specific depth. At a beam dose of cm -2, the superconducting parameters achieve the optimal values at which the influence of the lattice damage by ion implantation, as well as the impact of the Co ion concentration are balanced. A stable superconducting percolation path is created for the Co-ion peak concentration range from cm -3 to cm -3.

40 P8 Growth of Yttria Stabilized Zirconia on Flexible Muscovite Substrate by van der Waals Epitaxy Y.H. Juan 1, P.C. Wu 1, Y.P. Lin 1 Y.H. Chu 123 * 1 Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan 2 Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan 3 Department of Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan Yttria-stabilized zirconia (YSZ) is an outstanding material with high ionic conductivity for electrolytes of solid oxide fuel cell (SOFC) which can be a highly compelling way for generating electricity in the coming future. For the past few years, flexible device developed rapidly and it turns to higher demand. To develop YSZ thin film for flexible device, we demonstrate the device by growing high quality epitaxial YSZ thin film on transparent and flexible muscovite via van der Waals epitaxy. The structural characteristics of YSZ/muscovite heterostructure were analyzed by X-ray diffraction. Also, high resolution transmission electron microscopy was applied to confirm the epitaxial relationship and to examine the interface quality. The surface morphology was revealed by atomic force microscopy. The electrical property was measured via AC impedance spectroscopy to present the excellent ionic conductivity of YSZ films. Furthermore, the measurement of AC impedance under different bending radius gage was conducted to validate the property of the YSZ ionic conductor. In the present results, we successfully demonstrate a significant concept of creating a highly flexible SOFC electrolyte

41 P9 SrTiO3/ZnO Heterostructure for Transparent and Flexible Water Splitting Photoelectrode Pei-Chun Wang 1, Yung-Jung Hsu 1 1, 2, 3 and Ying-Hao Chu 1 Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan 2 Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan 3 Department of Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan Transparent and flexible applications have captured extensive attention recently due to the intriguing functionalities and great potential influencing our daily life. Muscovite mica is proposed to be a novel substrate recent years owing to the advantages of good transparency and highly mechanical flexibility. This study shows a combination of water splitting photoelectrode and transparent flexible features. We use pulsed laser deposition process to fabricate SrTiO3/ZnO bilayer on muscovite. X-ray diffraction is carried out to confirm the heterostructure. The optical properties are investigated by ultraviolet visible spectroscopy and photoluminescence analysis. From PL analysis, the charge carrier separation is enhanced in this heterostructure to improve the photoactivity. SrTiO3/ZnO photoelectrode not only shows good transmittance in visible light region but also exhibits superior performance on photoactivity. Moreover, the photocurrent is steady under different bending condition. This study first demonstrates a pathway to flexible and transparent photoelectrode for developing innovative devices on water splitting.

42 P10 Revolutionary Thin Film with Transitional Composition * Yu-Hong Lai 1, Ying-Hao Chu 1,2,3 1 Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan 2 Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan 3 Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan yhchu@g2.nctu.edu.tw The coupling between crystal structure and physical property is an interesting topic which has captured significant attention. In the past, it was difficult to arbitrarily tune the structure of substance. Nowadays, with the progress of material engineering, we can precisely control the structure and then manipulate its physical characteristics. In this work, the selected compounds, NiO and ZnO with structure of rock salt and wurtzite respectively, are fabricated on SrTiO3 substrates in the form of thin films with compositional gradient from NiO to ZnO by laser MBE system. From XRD measurement, it implies the array of ZnO follows structure of NiO. In addition, TEM, STEM and EDS analyses prove the whole structure is rock salt and the gradient exists indeed. Furthermore, in contrast with direct band gap of ZnO with wurtzite structure, the absorption spectrum exhibits that ZnO with rock salt structure has an indirect band gap, which confirms that structures really affect physical performance. This study not only makes a breakthrough in material science but demonstrates a pathway to tune properties by process of composition gradient.

43 P11 Three-dimensional massive Dirac electrons in Sr3PbO antiperovskite S. Suetsugu 1, K. Hayama 1, K. Kitagawa 1, A. W. Rost 2, J. Nuss 2, C. Mühle 2 and H. Takagi 1, 2 1 Department of Physics, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo , Japan 2 Max Planck Institute for Solid State Research, Heisenbergstrasse 1, Stuttgart, Germany Three-dimensional (3D) Dirac semimetals with 3D linear dispersion in bulk have been attracting considerable interest because of their expected unconventional properties such as liner magnetoresistance (MR) and giant diamagnetism. Recently, a family of cubic antiperovskite, A3TtO (A = Ca, Sr, Ba; Tt = Sn, Pb), was theoretically proposed as a candidate system for 3D massive Dirac electrons [1]. We are revealing the evidence for the presence of 3D Dirac electrons in Sr3PbO, one of the antiperovskite family. Magnetotransport measurements show linear MR (Fig.1) by light mass carriers of a few percent of free electron. NMR spin lattice relaxation rate 1/T1 with crossover from Korringa like T-linear to T 3 dependence reflects the density of states D(E) ~ E 2 for 3D Dirac electrons. By the combination of bulk magnetic susceptibility, NMR Knight shift and spin lattice relaxation rate, we observed giant diamagnetism of ~ 10-4 emu/mol with the magnitude dependent on carrier density (Fig.2). In this poster session, we will discuss the results which supports the presence of 3D Dirac electrons and the giant diamagnetism in Sr3PbO antiperovskite. Fig.1 Liner MR Fig. 2 Magnetic susceptibility and Knight shift

44 P12 Flexible Nonvolatile Transistor based on Aluminum-doped ZnO/ Pb(Zr0.7Ti0.3)O3 Heteroepitaxial Structure Meng-Fu Tsai 1, Jie Jiang 2, * 1, 3, 4 Ying-Hao Chu 1 Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan 2 Key Laboratory of Low Dimensional Materials and Application Technology of Ministry of Education, Xiangtan, Hunan, China 3 Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan 4 Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan RM#709, BLD6, No.1001, Daxue Rd., East Dist., Hsinchu City 300, Taiwan; yhchu@g2.nctu.edu.tw With the rise of Internet of Things, the demand for the device is dramatically increasing. In addition, the presence of flexible device also has been attracted a lot of attention. The flexible ferroelectric field-effect transistor (FeFET) has the advantage of high speed, nonvolatility, low-power consumption, and the compatibility of wearable devices. However, the ferroelectric oxide performance is restricted since the traditional flexible substrates show poor thermal stability. In this study, we select mica as substrate because it shows good thermal stability and flexibility. We demonstrated flexible FeFET on mica substrates, using epitaxial aluminum doped zinc oxide (AZO) film as the semiconductor channel layer and epitaxial Pb(Zr0.7Ti0.3)O3(PZT) film as a ferroelectric gate dielectric. The thermal stability and flexibility of the PZT film on the mica substrate has confirmed with various bending radius measurement and different temperature measurement. The 1T type bottom gate transistor which is made up of AZO on PZT film shows excellent transistor characteristics, with a drain-to-source voltage of 10V, the current through the AZO/PZT interface was characterized. The on/off current ratio is higher than 10 3 between +10 to -10V of the gate voltage. This study successfully demonstrated inorganic and flexible FeFET for next-generation smart devices with high thermal stability in flexible electronic systems..

45 P13 High-pressure phase diagram by NMR and magnetization study on hyperhoneycomb β-li2iro3 Y. Hayashi 1, K. Kitagawa 1, S. Sasaki 1, T. Takayama 2 and H. Takagi 1,2 1 Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo , Japan 2 Max Planck Institute for Solid State Research, Heisenbergstrasse1, Stuttgart, Germany Kitaev spin liquid is a ground state of the model in which S=1/2 spins have bond-dependent ferromagnetic Ising interaction on 2D honeycomb lattice [1]. It has been intensively studied since its realization was proposed by Jeff=1/2 pseudospins in honeycomb iridates [2]. Kitaev spin liquid also appears as a ground state on 3D variant of honeycomb lattice called hyperhoneycomb lattice (Fig.1). The realization is expected in β-li2iro3. However at ambient pressure β-li2iro3 shows a complex magnetic order. The field-induced ferromagnetic moment can be suppressed by application of high pressure [3], which indicates possible pressure-induced Kitaev spin liquid. On the other hand, it is known that higher pressure gives Ir dimer state [4]. We synthesized β-li2iro3 single crystal and measured magnetic susceptibility and NMR under high pressure. We observed transition in high temperature as a decreasing in magnetic susceptibility and Knight shift (Fig.2), consistent with dimer formation. However large magnetic fluctuation of relaxation rate 1/T1 and field-, angle- dependence of transition temperature in Knight shift 300 indicate that the dimer state is possibly different from PM conventional singlet dimer. 200 Fig.2 Phase diagram of Dimer β-li phase 2IrO 3. Transition points 100 by magnetic susceptibility (circle), NMR (cross) and Fig.1 Hyperhoneycomb lattice. XRD (triangle)[4]. Non-collinear P (GPa) [1] A. Kitaev, Ann. Phys. (N.Y.) 321, 2 (2006) [2] G. Jackeli and G. Khaliullin, Phys. Rev. Lett. 102, (2009) [3] T. Takayama et al., Phys. Rev. Lett. 114, (2015) [4] L. S. I. Veiga et al., Phys. Rev. B. 96, (R) (2017) T c (K) 6

46 P14 Helicity-Dependent THz Emission from Topological Insulator Sb2Te3 Chien-Ming Tu 1,2,3, Yi-Cheng Chen 1, Pei-Yu Chuang 4, Ming-Yu Lin 4, Chih-Wei Luo 1, Jiunn-Yuan Lin 5, Cheng-Maw Cheng 6, Jung-Chun A. Huang 4, Way-Faung Pong 2 and Takayoshi Kobayashi 1,7 1 Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan 2 Department of Physics, Tamkang University, Tamsui, Taiwan 3 Department of Physics, Lund University, P.O. Box 118, SE Lund, Sweden 4 Department of Physics, National Cheng Kung University, Tainan, Taiwan 5 Institute of Physics, National Chiao Tung University, Hsinchu, Taiwan 6 National Synchrotron Radiation Research Center, Hsinchu, Taiwan 7 Department of Engineering Science, The University of Electro-Communications, Tokyo, Japan Topological insulators represent a new quantum phase of matter with topological surface states that shows time-reversal protection from backscattering due to spin-momentum-locking. Recently, some studies demonstrate that helicity-dependent photocurrent on TIs can be manipulated by the polarization of incident light. Reversing the helicity of circular polarized light reverses the direction of the helicity-dependent photocurrent. These works highlight the potential of TIs on applications of spintronics in the future [1,2]. Here we demonstrate the terahertz emission spectroscopy of Sb2Te3 thin films under the excitation of ultrafast optical pulses of different helicity. In the oblique optical incidences, the polarity-reversals of the emitted terahertz waveform were observed as the polarization of optical pulse was changed from right-hand-circular-polarization to left-hand-circular-polarization. The helicity of optical pulses changes from +1 to -1 as well. In normal optical incident, no polarity-reversal of terahertz waveform was observed. A model based on transient photocurrent and optical rectification describes the experimental results very well, and the signals of the TSSs are extracted from bulk contributions. Comparison with the recent results on time-resolved and angle-resolved photoemission spectroscopy measurements, the phenomena agree with the spin-polarized photocurrent of topological surface states [3]. [1]. J. W. McIver, et al, Nat. Nanotechnol. 7, (2012). [2] C. Kastl, et al, Nat. Commun. 6, 6617 (2014).

47 P15 Quantum Liquid of Honeycomb Iridate K. Kitagawa 1, T. Takayama 2, Y. Matsumoto 2, Y. Kishiomoto 3, R. Takano 1, H. Takagi 1,2 1 University of Tokyo, Dept. of Physics, , Tokyo, Japan, 2 Max-Planck-Institute for Solid State Research,70569, Stuttgart, Germany 3 Kochi University, Graduate School of Integrated Arts and Sciences, , Kochi, Japan Pseudospins, Jeff=1/2, arranged on (hyper)honeycomb lattice is a promising realization of Kitaev quantum spin liquid (QSL) [1], which is an exactly solvable 2D model after introducing Mayorana operators. Nevertheless, all of the previously known honeycomb ruthenates/iridates turned out to have a long-range magnetic ordering. We recently found the first QSL material as a candidate for Kitaev QSL: 2D honeycomb H(D)3LiIr2O6 where the inter-honeycomb-layer Li ions are replaced by H(D) ions. Any signature of ordering was observed in magnetic susceptibility, specific heat, or XMCD, suggestive of the realization of QSL. To explore QSL physics and exclude the possible glassy ordering, we conducted local probe measurements, 1 H/ 2 D/ 6,7 Li-NMR. In all these materials, the low temperature state is free from static magnetism (see Fig. 1 for an example). Fig. 1 7 Li-NMR spectra of H3LiIr2O6.

48 P16 Hydrogen Insertion in Anti-perovskite Nitrides, Mn3CuN and Ca3BiN Yoshinobu Nakamura 1, Koshi Takenaka 2, Akira Kishimoto 3, Masaru Miyayama 1 and Hidenori Takagi 4,5 1 Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, Hongo Bunkyo-ku Tokyo, Japan, 2 Nagoya University, Japan 3 Okayama University, Japan, 4 Graduate School of Science, The University of Tokyo, Japan, 5 MPI, Germany Anti-perovskite families have the formula of B3AN, whose crystal structure is fcc-b3a crystal reinforced by nitrogen insertion. These materials are known to possess interesting physical properties derived from the interplay between magnetism and crystal lattice, such as colossal magneto-striction, negative thermal expansion, and canonical spin-glass among other things.[1,2] Interestingly, anti-perovskite structure permits the introduction of large amount of point defects, and/or interstitial atoms due to its elastic crystal lattice and these lattice defects often induce a perturbation in its electrical, mechanical or magnetic properties[3]. Here, we are going to introduce lattice defects of not only nitrogen deficiencies but interstitial hydrogen into anti-perovskite nitride families and try to modify their transport or other physical properties. As mother materials for hydrogen insertion, two different classes of anti-perovskite nitrides, (1) covalent intermetallic compound, Mn3CuN, and (2) ionic compound, Ca3BiN were selected. Hydrogen plasma treatment was conducted for the insertion of hydrogen into the interstitial positions of an anti-perovskite crystal lattice. The crystal structures of both Ca3BiN and Mn3CuN are both cubic whose space group is P3-m3. It was noteworthy that after the hydrogen plasma treatment, the crystal symmetry of Ca3BiN changed from cubic to tetragonal (P4/mmm), while the crystal lattice of Mn3CuN was isotropically expanded remaining its cubic symmetry. These results indicate that the mechanisms of hydrogen insertion are different between ionic compound, Ca3BiN and covalent compound, Mn3CuM. Detail in their transport properties will be reported in the presentation. References [1] K.Takenaka, and H.Takagi, Appl. Phys. Lett., 94 (2009) [2] S. Iqbal, et.al, J. Electronic Mater., 45(8) (2016) 4188 [3] K.Takenaka, et.al, J. Phys Soc., Jpn, 79(7) (2010)

49 P17 Phase control of Dirac node electrons in perovskite-type AIr1-xSnxO3 thin films (A = Sr, Ca) M. Negishi 1, N. Hiraoka 1, D. Nishio-Hamane 2, H. Ohsumi 3, and H. Takagi 1, 4 1 Dept. of Physics, Univ. of Tokyo, Tokyo, Japan 2 Institute for Solid State Physics, Univ. of Tokyo, Kashiwa, Japan 3 RIKEN Spring-8 Center, Sayo, Japan 4 Max Planck Institute for Solid State Research, Stuttgart, Germany It is a challenging issue to reveal how electron correlation works on Dirac materials, which have nodes with linear dispersion in their band structure and exhibit exotic phenomena such as high-mobility carriers and non-trivial topology. We are interested in perovskite-type iridate AIrO 3 (A = an alkaline earth metal), which is a paramagnetic semimetal with a Dirac line node protected by the time-reversal and crystal symmetry [1]. Recently a transition to a weak ferromagnetic insulator was discovered at a low temperature in Sn doped SrIrO 3 [2]. We conceived the idea to introduce and control electron correlation in a line node semimetal AIrO 3 by Sn substitution of Ir sites. We grew epitaxial thin films of perovskite SrIr 1-xSn xo 3 (SISO) and CaIr 1-xSn xo 3 (CISO) on SrTiO 3(001) substrates by pulsed laser deposition. A weak ferromagnetic moment appeared in the c axis of the bulk unit cell below T c. In the magnetically ordered state, an antiferromagnetic ordering of Ir pseudospins was detected by a resonant x-ray diffraction, indicating that the origin of the weak FM is a canted anti-ferromagnetism due to the Dzyaloshinskii-Moriya interaction. Semimetal-insulator transition concomitant with the appearance of the weak ferromagnetism was observed in SISO, while CISO became simply insulating by the substitution. A hysteretic magneto-resistivity and an anomalous Hall effect were observed in the magnetic regime. We identified magnetic phase diagrams for both SISO and CISO from those weak FM-driven transport properties (Fig. 1). A magnetic critical point is located around x ~ 7.5% for SISO, and, surprisingly, around x ~ 0% for CISO, respectively. We suggest that the different band width modulates an effective strength of electron correlation and results in such different phase diagrams. [1] J.-M. Carter et al., PRB 85, (2012). [2] Q. Chi et al., PRL 117, (2016). Fig.1: Phase diagrams of AIr 1-xSn xo 3 thin films. Temperature T (K) SrIr 1-x Sn x O 3 Thin Film Mag. Trans. (MR) Mag. Trans. (SQUID) SM-Ins. Trans. (RT) Non-Mag. Semimetal Weak FM Semimetallic Weak FM Insulating Substitution Ratio x 0.20 Temperature T (K) SM CaIr 1-x Sn x O 3 Thin Film Mag. Trans. (MR) Mag. Trans. (SQUID) Non-Mag. Insulating Weak FM Substitution Ratio x 0.20

50 P18 Quantum Anomalous Hall Effect with Higher Chern Numbers in Electron-Doped CrSiTe3: A First-Principles Prediction Sungmo Kang, Seungjin Kang, and Jaejun Yu * Department of Physics and Astronomy, Center for Theoretical Physics, Seoul National University, Seoul 08826, Korea The nontrivial topology of electronic band structure can give rise to many novel phenomena like the quantum spin Hall effect (QSHE) or the quantum anomalous Hall effect (QAHE). A Chern insulator is such a topological state of matter exhibiting a nonzero quantized Hall conductivity without an external magnetic field. There have been several experimental efforts to realize QAHE by doping magnetic impurities into topological-insulator thin films. Here we report that the Chern insulator can be realized in a single layer of electron-doped CrSiTe3. We have performed first-principles density-functional-theory calculations to find the minimum energy configuration for both atomic and magnetic structures and determined that the ground state of pristine CrSiTe3 is a ferromagnetic insulator. We use the Wannier function to calculate the Berry curvatures and prove the nontrivial Chern numbers for the conduction bands consisting of mostly Cr eg orbitals hybridized with neighboring Te p orbitals in the honeycomb-lattice network of CrTe6 octahedrons. Further, we demonstrate that the electron-doping can raise the Fermi level to the middle of the eg manifold, which opens up a band-gap of about 20 mev. Consequently, the electron-doped CrSiTe3 becomes a QAHE insulator with higher Chern numbers. The origin of higher Chern numbers is attributed to the presence of multiple Dirac cones in the eg-manifold band structures without spin-orbit coupling, together with the broken time-reversal symmetry of the ferromagnetic CrSiTe3. We confirm that the nontrivial topology of the electron-doped CrSiTe3 remains robust in its bulk structure by showing the chiral edge states by carrying out the edge state calculation. Our result suggests that there is a new family of Chern insulator materials in the form of MAX2- or MX3-type two-dimensional materials. * Work supported by the National Research Foundation of Korea (no. 2017R1A2B ).

51 P19 Mechanically Tunable Nonlinear Dielectrics Deng-Li Ko, 1,* Jie Jiang, 2 Huang Jun Wei, 1 Ying-Hao Chu 1,3,4 1 Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan 2 Key Laboratory of Low Dimensional Materials and Application Technology of Ministry of Education, Xiangtan, Hunan, China 3 Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan 4 Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan RM#709, BLD6, No.1001, Daxue Rd., East Dist., Hsinchu City 300, Taiwan; yhchu@g2.nctu.edu.tw In the past decade, strain engineering has been used to markedly manipulate characteristics of dielectric materials such as increasing tunability. However, the ways to apply strain into materials such as hydrostatic pressure, strong magnetic, electric and lattice mismatch are difficult to achieve in general environment and our daily life. In this study, we adopt flexible muscovite mica substrate to surmount this obstacle and fabricate (Ba0.5Sr0.5) TiO3 (BSTO) thin film which has high and tunable dielectric constant on mica substrate via van der Waals epitaxy. The combination of X-ray diffraction and high-resolution transmission electron microscopy was conducted to reveal the heteroepitaxy of the BSTO/muscovite system. The dielectric behaviors against mechanical bending were highlighted by the capacitance-voltage measurement under various bending conditions, ranging from 5~15 mm radius of curvature including tensile and compressive strain. In the bending measurement, the dielectric constant of BSTO thin films with different thicknesses was altered nonlinearly from -8% to 13% compared with the unbent state. Furthermore, there is also a release test after the bending measurement to confirm that the BSTO heteroepitaxial structures maintain the physical and tunable dielectric properties. Such a flexible BSTO/muscovite system contributes a path way to apply strain on thin film and develop a flexible and tunable dielectric material. Keywords: Flexible dielectric materials, Barium strontium titanite (BaxSr1-x) TiO3, muscovite mica, van der Waals epitaxy.

52 P20 Domain Switching Kinetics and Relaxation of Transparent and Flexible Ferroelectric Heterostructures Pao-Wen Shao 1, Chun-Hao Ma 1, Meng-Fu Tsai 1 and * Ying-Hao Chu Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan 2 Department of Electrophysics, National ChiaoTung University, Hsinchu, Taiwan 3 Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan *1001 Ta Hsueh Road, Hsin-Chu, Taiwan 30010, ROC; crag418@gmail.com From the past decades, wearable electric components have been regarded as a promising scenario for novel technology development. Benefitted from flexible muscovite substrates, fabricating wearable electric components becomes reality. However, the fundamental performance of these novel materials under strain states needs further confirmation. In this approach, we investigated the time-dependent domain wall motion in transparent epitaxial (Pb0.9La0.1)(Zr0.7Ti0.3)O3 thin film by piezoresponse force microscopy(pfm). Based on applying voltage via probing tip, partial reversal of polarization generated, which give us insight into the mechanism of domain relaxation. Under the circumstance of bending at reducing radius, the increasing strain is accompanied on the model of ferroelectrics/ bottom electrode/ mica substrates. In comparison with traditional Pb(Zr0.7Ti0.3)O3 ferroelectric thin film, (Pb0.9La0.1)(Zr0.7Ti0.3)O3 thin film not only exhibits brilliant transparency, but it also reveals comparable retention behavior. Furthermore, this work quantitatively identifies the mechanism that controls the propagation of the domain under bending status. [1] Jiang et al., Sci. Adv. 2017; 3: e

53 P21 Magnetic field angle-dependent XMCD study of L10-ordered FePt thin films with perpendicular magnetic anisotropy K. Ikeda1, T. Seki2, G. Shibata1, S. Sakamoto1, Y. Nonaka1, Z. Chi1, Y.-X. Wan1, M. Suzuki1, M. Sakamaki3, K. Amemiya3, K. Takanashi2, A. Fujimori1 1 Department of Physics, University of Tokyo, Tokyo, Japan 2 Institute for Materials Research, Tohoku University, Sendai, Japan 3 Institute of Materials Structure Science, KEK, Tsukuba, Japan In order to increase the storage density of magnetic recording media, magnetic thin films with large perpendicular magnetic anisotropy (PMA) have been extensively studied. L10-ordered FePt is one of the most promising materials due to its large PMA. However, the precise origin of the PMA remains controversial [1]. According to the perturbation-calculation study by van der Laan [2], the magnetic anisotropy energy (MAE) can be expressed by two terms, one is the spin-conservation term and the otheris the spin-flip term. Ueda et al. [3] have shown a large contribution of the spin-flip term to the MAE of L10-ordered FePt by first-principles calculation. However, no experimental proof has been obtained so far. In this study, we have performed Fe L- edge magnetic field angle-dependent x-ray magnetic circular dichroism (XMCD) [4] in order to deduce the MAE and the magnetic dipole moment which contributes to the spin-flip term. Figure 1 shows the results of the measurements of L10-orderd FePt thin films with different long-range chemical order degree S. One can see that the electric quadrupole moment Qzz which represents the magnetic dipole moment decreases with increasing S. [1] K. Ikeda et al., Appl. Phys. Lett (2017). [2] G. van der Laan, J. Phys.: Condens. Matter 10, 3239 (1998). [3] S. Ueda et al., Appl. Phys. Lett. 109, (2016). [4] G. Shibata et al., npj.quantum Mater., accepted. Fig. 1. Magnetic field dependence of Fe effective spin moments measured by Fe L- edge XMCD.

54 P22 Transparent (Ba,La)SnO3/Muscovite Heteroepitaxy for Flexible Optoelectronics and Thermoelectric *C.Y. Yang 1, M. Yen 1, K.H. Kim 2 1, 3, 4, and Y.H. Chu 1 Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan 2 CeNSCMR, Department of Physics and Astronomy, Seoul National University, Seoul , Republic of Korea 3 Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan 4 Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan yhchu@g2.nctu.edu.tw Over the past decade, there have been dramatic technological advances in portable electronics, flexible electronics, and numerous other devices that feature transparent electrodes. Transparent conducting oxides (TCO) have served as fundamental components in advanced optoelectronic devices spanning solar cells, light emitting diodes, thin film transistors, photocatalysis, and flat panel displays. As there is an increasing demand in next-generation devices with high performance, improving the mobility is an essential issue for developing transparent logic devices. Lanthanum-doped barium stannate (Ba,La)SnO3 (BLSO) is a new TCO with high electron mobility in perovskite structure which captured significant attention in the last decade. In this study, we intend to grow BLSO thin film heteroepitaxially on flexible transparent mica substrate by pulsed laser deposition (PLD) process to achieve the flexible TCO with the electron mobility higher than 100 cm 2 /(Vs). So far, we have fabricated heteroepitaxial BSLO thin film which has high transmittance up to 90%, and its mobility reaches 16 cm 2 /(Vs). Furthermore, BLSO thin film can stand less than 5mm bending radius with the change of resistance no more than 4%. The transport properties still remain outstanding after 1000 times bending cycles. The combination of BLSO and muscovite exhibits not only excellent electrical properties but also optical and flexible characteristics. Furthermore, we will combine this system with glass as a thermoelectric device to develop a new smart window transferring heat to electric energy. This offers a pathway not only to fabricate flexible transparent high-power functional devices for optoelectronic applications but to construct green-energy smart windows which is the indicator of the future buildings.

55 P23 Study of the Magnetic Structure of Single Crystal YBaCuFeO5 Using Inelastic Neutron Scattering Yu-Hui Liang 1, Chun-Hao Lai 1, Chin-Wei Wang 2, Shin-ichiro YANO 2, Kirrily C Rule 3, Dehong Yu 3, Yen-Chung Lai 4, Chao-Hung Du 1 1 Department of Physics, Tamkang University, New Taipei City, Taiwan 2 Neutron Group, National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan 3 Australian Center for Neutron Scattering, Australian Nuclear Science and Technology Organization, NSW 2232, Australia 4 National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan Using magnetization, dielectric constant on a high quality single crystal of YBaCuFeO5 (YBCFO), we demonstrate that the crystal shows two antiferromagnetic transitions at TN1 475 K and TN2 175 K. At TN2, the commensurate spin ordering transforms to a spiral magnetic structure with a propagation vector of ( h 2 k l 2 2 ± δ), where h, k, and l are odd, and the incommensurability δ is temperature dependent. In order to understand the dynamic behavior of the spiral magnetic ordering, we applied inelastic neutron scattering to study the spin ordering of the crystal YBCFO on the beamlines SIKA and PELICAN of ANSTO. On PELICAN, we focused on two phase regimes, commensurate (T=250) and incommensurate (T= 110 K), and observed both phases showing a very steep excitation behavior which could extend up to 5 mev. Further, on SIKA, the ICM phase (T=110 K) was observed to show the dispersion behavior in both Q and Energy spaces. The detailed study of the dynamic behavior of the spiral magnetic ordering of YBCFO is still under going. [1] Y.-C. Lai, et. al., J. Phys., 29, (2017) [2] Y. I. Joe, et. al., Nature Physics, 10, 421 (2014)

56 P24 Ferroelectric Properties of Epitaxial Bismuth Ferrite Thin Film on Flexible Muscovite Substrate Yu-Hao Tu 1, Jie Jiang 2, Ying-Hao Chu 1 1 Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan 2 Key Laboratory of Low Dimensional Materials and Application Technology of Ministry of Education, Xiangtan, Hunan, China Nowadays, the demand for high-efficiency electronic devices has increased dramatically. Traditional dynamic random access memory is widely used because of its low cost, but it also has an undeniable drawback that the memory state is volatile. To improve the drawbacks of conventional volatile memory devices, several new types of memories have been proposed. Among various kinds of memories, ferroelectric memory is one of the remarkable types due to its high endurance, high data storage density, low power consumption and non-volatile feature. Bismuth ferrite (BiFeO3) is considered to be a promising ferroelectric material because of its lead-free feature, strong spontaneous polarization (~90 μc/cm2 along [111]) and high Curie temperature (~1103K). All these advantages make it to be a prominent candidate material for ferroelectric memory. Additionally, owing to the development of portable and wearable devices, the flexible devices become a popular subject. Natural mineral muscovite possesses high transparency, high thermal and chemical stability. With a moderate thickness, it can also show great flexibility. Some previous studies have even proven that an epitaxial structure can be fabricated on muscovite substrate successfully. In this study, we try to deposit bismuth ferrite on flexible muscovite substrate to build up an epitaxial structure on muscovite. To investigate its characteristics, we use X-ray diffraction and atomic force microscopy to identify its structure and morphology, and then we measure the C-V and P-E loops for its electrical properties. Based on our results, it can make a strong contribution for further applications of flexible devices.

57 P25 Two-Dimensional Metal-Organic Framework Kagome Lattice with Non-Trivial Topological Band Structure Seungjin Kang 1, Santu Baidya 1,2, Choong H. Kim 1,2, and Jaejun Yu 1* 1 Center for Theoretical Physics, Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea 2 Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Korea The Chern insulator on a lattice without external magnetic field realizes so-called the quantum anomalous Hall effect. So far, the experimental realizations of Chern insulators have been devoted to magnetically doped topological-insulator thin films but demonstrated the effect at low temperatures due to small band gaps. Here we predict that a two-dimensional metal-organic framework of a single layer of transition-metal bis-dithiolene complex, M3C12S12 (M = Mn, Fe, Co), can become a ferromagnetic insulator with a nontrivial Chern number. Among various synthetic pathways leading to metal bis-dithiolenes, a particular choice of ligand, Benzene-hexathiol, connects metal cations to form a Kagome lattice. From the results of our first-principles density-functional-theory calculations together with a tight-binding analysis, we show that the sulfur and carbon-based ligands in a transition-metal bis-dithiolene complex are playing a key role in making the band structure of the complex topologically nontrivial. An unusual band inversion brings an almost flat band as the highest occupied band. The nontrivial topology of the flat band is confirmed to have a nonzero Chern number, quantized Hall conductivity, and the chiral edge states by using the Wannier function basis and Green s function approach. Our study shows that transition metal bis-dithiolene complexes are an important playground for obtaining novel electronic properties in two- dimensional metal-organic framework. * Work supported by the National Research Foundation of Korea (no. 2017R1A2B ).

58 P26 Dynamics of phase transitions in the orbital-ordered vanadates T. Kajita 1, Y. Obata 1, Y. Kakesu 1, M. Hoshino 1, Y. Sato 2, Y. Katayama 2, K. Ueno 2, and T. Katsufuji 1, 3 1 Department of Physics, Waseda University, Tokyo , Japan 2 Department of Basic Science, University of Tokyo, Tokyo , Japan 3 Kagami Memorial Laboratory for Material Science and Technology, Waseda University, Tokyo Ba1-xSrxV10O15 ( ) [1,2] and Ba1-xSrxV13O18 ( ) [3,4] have orbital and charge degrees of freedom in the V t2g states and exhibit phase transitions with the V trimerization caused by the orbital ordering of V t2g states. Recently, we found that these phase transitions are suppressed by rapid cooling and high temperature (HT) phase survives down to the lowest temperature as a metastable state. To reveal the relaxation behavior from the metastable HT phase to the LT phase in and , we performed time-dependent measurement of the resistivity and the magnetic susceptibility. We found that in the system, the slope of the magnetic susceptibility vs. time discontinuously changes at whereas the resistivity suddenly increases by 10 2 times at (> ). In the systems, such discontinuous changes were not observed but only a gradual decrease in the magnetic susceptibility and a gradual increase in the resistivity were observed. [1] T. Kajita et al., Phys. Rev. B 81, (R) (2010) [2] K. Takubo et al., Phys. Rev. B 86, (2012). [3] M. Ikeda et al., Phys. Rev. B. 83, (2011). [4] T. Kajita et al., Phys. Rev. B 96, (2017).

59 P27 Magnetotransport properties of Ba1-xSrxV13O18 K. Funahashi 1,Y. Kakesu 1,T. Suzuki 2,J. Checkelsky 2 and T. Katsufuji 1, 3 1 Department of Physics, Waseda University, Tokyo , Japan 2 Department of Physics, Massachusetts Institute of Technology, MA 02139, U.S.A. 3 ZAIKEN, Waseda University, Tokyo , Japan Vanadium oxides with mixed-valent V ions exhibit various intriguing ordered states arising from charge and orbital degrees of freedom. Ba1-xSrxV13O18, in which the average valence of V is +2.62, takes a hexagonal structure with the V ions on a quasi-face-centered-cubic lattice with periodically missing sites, and three phases appear in this series of compounds.[1-4] The high-temperature phase is characterized by spin-singlet V tetramers, whereas the low-temperature phase is characterized by V trimers, and another intermediate-temperature phase with charge ordering appears for x 0.3. We study the magnetotransport properties of Ba1-xSrxV13O18, especially in the low-temperature V trimer phase to clarify the nature of this anomalous phase. We found that the Hall coefficient exhibits strong temperature dependence below Ttr (the transition temperature into the low-temperature phase). Remarkably, there is large anisotropy in the Hall coefficient, and even signs are different for different directions of the electric current and the magnetic field. We also found that a positive magnetoresistance appears only at very low temperatures (T < 15K). Fig.1 Hall coefficient of SrV13O18 Fig.2 Magnetoresistance of SrV13O18 [1] M. Ikeda, T. Katsufuji et. al., Phys. Rev. B 82, (2010). [2] M. Ikeda, T. Katsufuji et. al., Phys. Rev. B 83, (2011). [3] T. Kanzaki, T. Katsufuji et. al., Phys. Rev. B 89, (2014). [4] T. Kajita, T. Katsufuji et al., Phys. Rev. B 96, (2017)

60 P28 Time-Resolved Angle-resolved Photoemission Spectroscopy by Using Femtosecond High Harmonic Generation Hao-Hsiang Jia 1, Xiang-Tang Luo 1, Hung-Wei Sun 1, Chih-Wei Luo 3, Cheng-Maw Cheng 2, Ming-Chang Chen 1, Ping-Hui Lin 2 1 Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, Taiwan 2 National Synchrotron Radiation Research Center, Hsinchu, Taiwan 3 Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan We have developed a time- and angle- resolved photoelectron spectroscopy (TR- ARPES) apparatus using high-harmonic generation (HHG) extreme ultraviolet light source. The probe beam we used is a nearly polarized 41.9 ev HHG light ( 10⁹ photons/sec ) was driven by 1035 nm laser ( 10 khz, 8 W, 160 fs ), while a small portion of the pulse energy was used as the pump. We have demonstrated that the HHG EUV beam is extremely stable ( 6 % rms) and has been tested for running more than one week continuously without any realignment and maintenance. This laser-based Tr- ARPES system has high stability and can be used to investigate ultrashort time scaled unequilibrium processes in solids which happens in ultrashort time scales. Keywords: ARPES, time-resolved, high harmonic generation, electronic structure, dynamic

61 P29 Electronic structure of single-crystalline black phosphorus Sae Hee Ryu 1,2 and Keun Su Kim 1 1 Department of Physics, Yonsei University, Seoul 03722, Republic of Korea 2 Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea Two-dimensional (2-D) crystals, atomically thin layered materials, have emerged as a novel class of materials for application in devices. Black phosphorus (BP) has promising device characteristics, such as moderate band gap, high mobility, and on-off ratio. We have studied the band structure of single-crystal BP with high-resolution angle-resolved photoemission spectroscopy (ARPES). The experimental spectra taken with various photon energies and light polarizations are analyzed, as compared to theoretical band calculations, which is overall in good agreement. This would provide a fundamental framework to understand various electronic and optical properties of BP and its thin films.

62 P30 Neutron Powder Diffraction Study of the Double Perovskite Oxides YBa(Cu1-xFex)2O5 Chun-Hao Lai ( 賴君豪 ) 1,Yen-Chung Lai ( 賴彥仲 ) 2, Chin-Wei Wang ( 王進威 ) 2, Hung-Cheng Wu ( 吳紘丞 ) 3, Chao-Hung Du( 杜昭宏 ) 1* 1 Department of Physics, Tamkang University, New Taipei City 25137, Taiwan 2 National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan 3 Department of Physics, National Sun Yat-Sen University, Kaohsiung 804, Taiwan Structural and magnetic properties of variety Cu/Fe ratio of the double perovskite YBa(Cu1-xFex)2O5 were investigated by using neutron powder diffraction (NPD) and susceptibility measurements. The crystal structures of all the samples are formed in a space group of P4/mmm with in the x range between 0.45 and Susceptibility measurements of YBaCuFeO5 exhibited two antiferromagnetic transitions at TN1 ~ 450 K and TN2 ~ 175 K, accompanied with two anomalous spin ordering. The refinement results show a commensurate (CM) phase with propagation vector Qc1 = (1/2 1/2 1/2), between TN1 and TN2, which as a collinear magnetic structure. Below TN2, two satellites of incommensurate (ICM) phase were observed at around each commensurate ones with Qi = (1/2 1/2 1/2 ± q), indicating the appearance of spiral magnetic structure [1]. Furthermore, these observations revealed that TN2 is very sensitive to the concentration of Fe, and explained the paradox of transition temperatures in the past reports. For x = 0.510, extra magnetic reflections emerge with a propagation vector Qc2 = (1/2 1/2 0), suggesting the coexistence of two commensurate magnetic phases with propagation vectors of (1/2 1/2 1/2) and (1/2 1/2 0), respectively. [1] M. Morin et al., PHYSICAL REVIEW B, 91, (2015).

63 P31 Magnetically-induced anisotropic charge distribution in La1-xSrxMnO3 thin films revealed by x-ray magnetic linear dichroism G. Shibata 1, K. Yoshimatsu 1,2, K. Ishigami 1, T. Harano 1, Y. Takahashi 1, S Sakamoto 1, Y. Nonaka 1, T. Kadono 1, M. Furuse 3, S. Fuchino 3, M. Okano 3, J.-i. Fujihira 4, A. Uchida 4, K. Watanabe 4, H. Fujihira 4, S. Fujihira 4, A. Tanaka 5, H. Kumigashira 2, T. Koide 2, and A. Fujimori 1 1 Department of Physics, University of Tokyo, Tokyo, Japan 2 Photon Factory, High Energy Accelerator Research Organization, Tsukuba, Japan 3 National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan 4 Fujihira Co.,Ltd., Tsukuba, Japan 5 Department of Quantum Matter, Hiroshima University, Higashi-Hiroshima, Japan La1-xSrxMnO3 (LSMO) is a perovskite-type oxide which exhibits novel magnetic properties such as colossal magnetoresistance and half metallicity. Its magnetic properties are largely affected by the preferential orbital occupation in the Mn 3d bands. In order to clarify the relationship between the spin states and orbital occupation of Mn, we have performed x-ray magnetic linear dichroism (XMLD) experiments on LSMO (x=0.4) thin films grown on SrTiO3 (001) (STO) substrates. Figure 1 schematically describes the experimental geometry. The magnetic field is applied perpendicular to the incident x rays using a vector-type magnet [1,2]. Since the LSMO film has C4 crystal symmetry around the light axis, the dichroism signal should solely originate from spins. Figure 2 shows the XMLD spectra at the Mn L2,3 edges for various thicknesses. The spectral intensities are proportional to the square of the net magnetic moments M 2, indicating that the XMLD mainly arises from the ferromagnetic phase in the films rather than the antiferromagnetic phase. By comparison with cluster-model calculations, it has been shown that the electron orbital is elongated along the spin direction due to spin-orbit interaction. [1] M. Furuse et al., IEEE Trans. Appl. Supercond. 23, (2013).