Mn in GaAs: from a single impurity to ferromagnetic layers
|
|
- August Lambert
- 5 years ago
- Views:
Transcription
1 Mn in GaAs: from a single impurity to ferromagnetic layers Paul Koenraad Department of Applied Physics Eindhoven University of Technology Materials D e v i c e s S y s t e m s COBRA Inter-University Research Institute on Communication Technology KITP, 17 April 006 1
2 Mn in GaAs: from a single impurity to ferromagnetic layers D e v i c e s Materials S y s t e m s COBRA Inter-University Research Institute on Communication Technology Outline Introduction Single impurities Symmetry breaking Coupled impurities Delta doping layers Albuquerque, 16 July 005
3 Mn-Doping Atoms 3
4 Electronic Structure magnetic doping: a part of the atoms in the crystal is replaced by magnetic transition metal impurities 4sp 4sp 4sp 4sp Ga-atom GaAs 3d 3d 3d 3d 3d Mn on Ga-site in GaAs (3d 5 +h) 4sp 4sp 4sp Mn-atom GaAs h 3d 5 3d 3d 3d 3d 3d Mn p-d interaction results in anti-ferromagnetic alignment 4
5 Electronic Structure Mn-atom in GaAs 3d 3d 3d 3d 3d d-states split by cubic crystal symmetry Anti-bonding (bound acceptor state) Impurity band resonant with the valence band States with Γ 15 symmetry split due to SO interaction 4sp Valence band states GaAs 4sp 4sp 4sp 113 mev ground state populated at T=0 when in neutral condition triplet T doublet Γ 15 Γ 1 E The p-d coupling to is strongest for d-states with Γ 15 symmetry Tang en Flatté PRL 9, (004) 5
6 Assessment at the Atomic Scale by Cross-Sectional STM 15 nm * 30 nm STM tip 9 nm * 8 nm InAs self-assembled quantum dot in GaAs Two Si impurities in GaAs 110-surface cleaved III/V sample UHV (10-11 torr) 6
7 Impurity Imaging Iso-electronic impurities Charged impurities InGaAs-wetting layer 30 nm * 30 nm Counting demonstrated up to 40 % Si:InP 100 nm * 100 nm sharp (surface Si-atoms) diffuse (sub-surface Si-ions) 7
8 Scanning Tunneling Microscopy on Semiconductors z I E c E F E v E gap E F E F ev ev E v E F E C V sample sample tip 8
9 Scanning Tunneling Microscopy on Semiconductors Positive sample voltage (empty states) Negative sample voltage (filled states) z E F z E c E F E v E gap ev E c E F E v E gap E F ev sample tip sample tip Depletion, accumulation, inversion 9
10 A and A o Charge States of Mn Ionized Mn A (V=-1.1 V) Neutral Mn A o :(ion + hole) (V=+1.1 V) [110] [001] 70 nm * 70 nm 3*10 18 /cm nm * 70 nm Grown by J. De Boeck et al., IMEC, Belgium Same position is imaged at both voltages Contrast depends on depth of Mn-atom below cleaved surface 10
11 Manipulation of the Charge State by STM tip Ionized Mn acceptor Neutral Mn acceptor E c Negative sample voltage E c Positive sample voltage A 0 I TUNNEL E v E F p-type sample A I TUNNEL tip E v E F p-type sample tip 11
12 A and A o Charge States of Mn Ionized Mn A (V=-0.9 V) Neutral Mn A o :(ion + hole) (V=+0.7 V) 14 nm * 14 nm Contrast is due to Coulomb field [110] [001] Tunneling to the bound hole (Mn in ~ 3 rd sublayer) 5.6 nm * 5.6 nm 1
13 Spectroscopic Signature of Mn Current map at +1. V away from Mn on the Mn 0,04 Current (na) 0,0 0,00 00x00 points p-type E v E F Mn 00 * 00 I(V)-curves taken around impurity -0,0 ~100 mev Binding energy Mn 113 mev E c E c E F Mn 0-0,8-0,4 0,0 0,4 0,8 1, 1,6 Bias (V) E v p-type sample tip 13
14 Contrast Mechanism Ionized acceptor Screened acceptor Negative sample voltage z Positive sample voltage z E F E c E c E gap ev E F E v E gap - E F ev E F E v p-type sample tip p-type sample tip Around charged acceptor bands bend upwards this increases current (height STM tip) Bright feature Around screened acceptor weak band bending. Due to impurity LDOS increase of current (height STM tip) Bright feature 14
15 Modeling of Impurity States in Semiconductors 15
16 16 Effective Mass Donor l=0 l=1 l= m=0 m=1 m=0 m=0 m=1 m= n=1 n= n=3 ε e ε hh ε lh J=1/ J=3/ m l n m l n m l n r o m l n e r z y x m k,,,,,,,, * 1 ψ ε ψ ε ε ψ = Pure s-like ground state ), ( ) ( ) 1 ( 0 0, 0 / 1 ϕ θ ψ Y r S = R ( ) * z y x e k k k m + + = ε
17 J=1/ ε e Luttinger Hamiltonian J=3/ ε hh (m J =3/) ε lh (m J =1/) H Lut ( k x, k y, k z ) ψ + V ( r) ψ = ε ψ i i i i Luttinger Hamiltonian H Lut ( k x, k y, k z ) = m o H + c b 0 hh + c H b 0 lh + b 0 H c lh + H 0 b c hh ψ i ϕ1 ϕ = ϕ 3 ϕ4 3/, + 3/ 3/, + 1/ 3/, 1/ 3/, 3/ 4-vector representation based on spin-projection H H hh lh = = b = c = ( kx + k y )( γ 1 + γ ) + kz ( γ 1 γ ) ( k + k )( γ γ ) + k ( γ + γ ) x 3γ ( k 3 3 x y [ γ ( k k ) iγ k k ] x 1 ik y y ) k z 3 z x 1 y γ 1, γ and γ 3 Luttinger parameters Spin-orbit coupling mixes the light and heavy hole bands in confined states γ = γ 3 isotropic dispersion 17
18 Effective Mass Acceptor Ground state components ψ 1 + ψ = ε ψ H Lut n, l, m n, l, m n, l, m n, l, m ε oε rr Isotropic dispersion ψ Y0,0 Y,0 0 Y = R + β R 0 Y, 0 0 3/,1 3/ 0 ψ 0 Y Y Y = R + β R Y, 1 3/ 0,0,0 1/ 0, Y l,m spherical harmonics R l radial distribution 3/ 3/ ψ 3/ ψ 1/ and their Kramers conjugates and Bir, Pikus in Symmetry and straininduced effects in semiconductors the ground state has a mixed s + d character l=0 l= m=0 m=0 m=1 m= + β 18
19 Effective Mass Acceptor ψ 1 + ψ = ε ψ H Lut n, l, m n, l, m n, l, m n, l, m ε oε rr Y0,0 0 Y,0 3/ 0 T Y,1 0 ψ E 3/ = R 0 + β R + β R 0 Y, Y, Y, + Y, [010] [100] [001] Cubic symmetry of crystal selects d-components l=0 l= m=1 l= m= m=0 m= T E + + β Ε β Τ 19
20 Effect of Crystal Anisotropy η=1 corresponds with isotropic dispersion Cut at 6 monolayer's trough impurity state along a 110 plane Effective mass model η=0 corresponds with a pure T symmetry [001] [010] η = βe β T 8 nm * 8 nm 110 plane [100] 0
21 Electronic Structure Tight Binding of Mn-acceptor Experiment J.-M. Tang M. Flatté, Iowa, US 6 nm * 6 nm [001] [110] Grown by J. De Boeck et al., IMEC, Belgium Effective mass model Yakunin et al. PRL 9, (004) 1
22 Real Space Fourier Space Experiment Mn in ~ 4 th sublayer Effective mass model = E T η β / β = 0 Tight-binding model (M. Flatté, University of Iowa) = E T η β / β 0 1 nm *1 nm 0.8 nm -1 * 0.8 nm -1 Yakunin et al. PRL 9, (004)
23 Improved Effective Mass Model Experiment Effective mass model Inclusion of anisotropy (γ γ 3 ) in the dispersion A. Monakhov & N. Averkiev, Ioffe Institute 3
24 Symmetry Breaking by crystal symmetry 4
25 Broken Symmetry Mn:GaAs Bulk or surface symmetry?? Zn:GaAs 6 nm * 6 nm [001] [110] 110-surface 1-10-surface Yakunin et al. PRL 9, (004) Mathieu et al. PRL 94, (005) 5
26 Inversion Asymmetry Figure: S. Loth, Goettingen Ga As impurity 110-surface 1-10-surface Mathieu et al. PRL 94, (005) 6
27 Inversion Asymmetry Ga As impurity 110-surface 1-10-surface Figure: S. Loth, Goettingen 7
28 Symmetry Breaking by strain 8
29 Stacked Quantum Dots 9 55 nm * 55 nm Grown by M. Hopkinson, Sheffield (UK) current image Bruls et al. APL 8, 3758 (003)
30 Lattice Constant Profile Growth direction 0,65 InAs/GaAs dot Lattice constant [nm] 0,60 0,55 0, Distance [nm] Grown by K. Pierz, PTB-Braunschweig, Germany nm * nm 30
31 Strained Mn impurity GaAs host QD (InAs) [001] [1-10] Fourier filtered experimental image Effective mass 31 nm * 33 nm Mn 1 Mn adsorbent Grown by J. De Boeck et al., IMEC, Belgium TBM 31
32 Strained Unstrained (a) Mn1 m m m1 m nm 60 nm * 60 nm Mn impurity [001] [1-10] 60 nm * 60 nm (b) Strained m m m1 m 1 Mn Mn 1 0,3 m 1 Mn 1 Mn Mn Measured height, nm 0, 0,1 m GaAs host Mn 1 QD (InAs) 0, Distance along [1-10] direction, nm Mn 3
33 Strained Mn impurity Unstrained Strained EMA [1-11] TBM [001] [110] 33
34 Symmetry Breaking Shallow Impurities 34
35 Broken Symmetry Shallow Impurities Be A 0 Co-doped GaAs:Be,Mn Mn A 0 30 nm * 30 nm [001] [110] 35
36 Shallow & Deep Acceptor states C:GaAs Be:GaAs Zn:GaAs Cd:GaAs Shallow E B = 6 mev E B = 8 mev E B = 31 mev E B = 35 mev Reusch et al. Univ. Of Gottingen C 6 mev Be 8 mev Zn Mahieu et al. PRL 94, (005) Cd 35 mev 30 mev Mn 113 mev Co 150 mev Zheng et al. APL 64, 1836 (1994) van der Wielen et al. PRB 63, (001) Mn:GaAs Deep Valence band E B = 113 mev Yakunin et al. PRL 9, (004) 36
37 Interaction with Surface Broken symmetry III V Broken symmetry III V X X Shallow Deep Zn:GaAs Effective localization radius of a neutral acceptor Mn:GaAs a 0 = m * E b 37
38 Spin-orbit Interaction 38
39 Spin-orbit Interaction 0.9 Acceptor with E b = 113 mev at 6 monolayers below surface 0.8 Split-off Energy (ev) N 7 Cd Al 13 Ga 31 In 49 Zn Mn P 15 As 33 Sb 51 [001] [110] 8 nm * 8 nm 39
40 Spatial Structure of Zn in GaP(110) Bulk GaP intentionally doped with Zn (~x10 18 cm -3 ) [001] [1-10] 11 nm * 8 nm 40
41 Anisotropy & Spin-orbit Interaction η=1 corresponds with isotropic dispersion Acceptor with E b = 113 mev at 6 monolayers below surface η=0 corresponds with a pure T symmetry Crystal anisotropy dominates see also Yakunin et al. PRL 9, (004) [001] [110] 8 nm * 8 nm 41
42 Missing link Topography image Fourier filtered image Zn in GaAs E b (Zn) = 30meV a 0 = 1.8nm Zn in GaP E b (Zn) = 70meV a 0 =~ 0.6nm! 10.5 nm * 7.5 nm 11 nm * 8 nm 6 nm * 4 nm 9 nm * 5 nm Mn in GaAs E b (Mn) = 110meV a 0 = 1nm 1 * 8 nm 9 nm * 6 nm 4
43 Symmetry of Impurities Mn in GaAs Zn in GaP Zn in GaAs O 8 T d A A T E T E A [001] [001] T E [100] [010] Effective mass Tight binding Ab-initio modelling [100] [010] [1-10] [001] [100] [010] Yakunin et al. PRL 9, (004) Figure: S. Loth [100] [110] S. Loth et al. PRL 96, (005) 43 Mathieu et al. PRL 94, (005)
44 Pairs of magnetic impurities 44
45 Mn-delta Doped Layers Intentional Mn concentration N= cm - Growth direction [001] 53 nm * 40 nm Grown by J. De Boeck et al., IMEC, Belgium 45
46 Interacting Impurities 5 th sub-surface layer surface atom sub-surface atom 6 nm * 6 nm Mn 0 Mn 1 Mn [1-10] [001] Separation 0.8 nm A. Yakunin et al. PRL 95, 5640 (005) Ga As Grown by J. De Boeck et al., IMEC, Belgium 1 nm * 10 nm 1 nm * 10 nm Separation 1.38 nm 46
47 Experimental TBM Simulation 0.8 nm 1.4 nm h h 3d 5 Mn Mn J.-M. Tang M. Flatté Iowa, US A. Yakunin PRL 95, 5640 (005) 6 nm * 6 nm 6 nm * 6 nm anti-parallel spin 3d 5 [1-10] parallel spin [001] 1 nm * 10 nm 1 nm * 10 nm 47
48 Delta layers 48
49 Impurity-Impurity Interaction Mn-Mn pair (70 nm) Mn-Mn pair (1.4 nm) Mn-As Ga pair nm * 140 nm 1 nm * 10 nm 60 nm * 80 nm
50 Directional Dependence Mn-overlap 10 0 d-character dominates far from impurity Calculated overlap % [010] [100] [001] 34% 10 - EMA [001] EMA [011] EMA [111] Mn-Mn separation r (nm) 50
51 Directional Dependence Mn-overlap 10 0 d-character dominates far from impurity Calculated overlap 10-1 TBM [001] TBM [011] TBM [111] 43% [010] [100] [001] 10-56% Mn-Mn separation r (nm) 51
52 Directional Dependence Mn-overlap 10 0 d-character dominates far from impurity Calculated overlap 10-1 TBM [001] TBM [011] TBM [111] 43% 3% [010] [100] [001] 34% 10 - EMA [001] EMA [011] EMA [111] 56% Mn-Mn separation r (nm) 5
53 Directional Dependence Mn-overlap A separation (nm) B Bohr radius 0.9 nm B A 3 d-character dominates far from impurity [010] [100] [001]
54 Directional Dependence Mn-overlap A [111] [011] [001] separation (nm) 0.5 B 1 Bohr radius 0.9 nm B A 3 d-character dominates far from impurity [010] [100] [001]
55 Overlap Expectation on [i,j,k] Plane 4*10 14 cm - (100%) 4*10 1 cm - (1%) Highest T curie on the [111] doping plane? [001] doping plane [011] doping plane [111] doping plane [001] [001] [001] [010] [100] [010] [100] [010] [100] 55
56 High Concentration Mn Delta Layers Local bonds surface Mn -3 V Mn in ionized state Local Coulomb potential 35 nm * 35 nm Grown at PDI, Berlin, Germany - V Ga 0.8 Mn 0. As delta layers (1*10 14 cm - ) -1. V 56
57 Acknowledgements A. Yakunin, C. Celebi, A. Silov, J.H. Wolter (TU/e) W. Van Roy, J. De Boeck (IMEC-Leuven, Belgium) X. Guo, K. Ploog (PDI-Berlin, Germany) J.M. Tang, M. Flatté (University of Iowa, USA) A. Monakhov, N. Averkiev (Ioffe-institute, Russia) 57
Minimal Update of Solid State Physics
Minimal Update of Solid State Physics It is expected that participants are acquainted with basics of solid state physics. Therefore here we will refresh only those aspects, which are absolutely necessary
More informationWarping a single Mn acceptor wavefunction by straining the GaAs host
ARTICLES Warping a single Mn acceptor wavefunction by straining the GaAs host A. M. YAKUNIN 1 *,A.YU.SILOV 1,P.M.KOENRAAD 1,J.-M.TANG 2,M.E.FLATTÉ 2,J.-L.PRIMUS 3, W. VAN ROY 3,J.DEBOECK 3,A.M.MONAKHOV
More informationDefense Technical Information Center Compilation Part Notice
UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADP012727 TITLE: Correlated Dopant Distributions in Delta-Doped Layers DISTRIBUTION: Approved for public release, distribution
More informationDirect and Indirect Semiconductor
Direct and Indirect Semiconductor Allowed values of energy can be plotted vs. the propagation constant, k. Since the periodicity of most lattices is different in various direction, the E-k diagram must
More informationLecture contents. Stress and strain Deformation potential. NNSE 618 Lecture #23
1 Lecture contents Stress and strain Deformation potential Few concepts from linear elasticity theory : Stress and Strain 6 independent components 2 Stress = force/area ( 3x3 symmetric tensor! ) ij ji
More informationSpins and spin-orbit coupling in semiconductors, metals, and nanostructures
B. Halperin Spin lecture 1 Spins and spin-orbit coupling in semiconductors, metals, and nanostructures Behavior of non-equilibrium spin populations. Spin relaxation and spin transport. How does one produce
More informationThree Most Important Topics (MIT) Today
Three Most Important Topics (MIT) Today Electrons in periodic potential Energy gap nearly free electron Bloch Theorem Energy gap tight binding Chapter 1 1 Electrons in Periodic Potential We now know the
More informationGa and P Atoms to Covalent Solid GaP
Ga and P Atoms to Covalent Solid GaP Band Gaps in Binary Group III-V Semiconductors Mixed Semiconductors Affect of replacing some of the As with P in GaAs Band Gap (ev) (nm) GaAs 1.35 919 (IR) GaP 2.24
More informationLecture 18: Semiconductors - continued (Kittel Ch. 8)
Lecture 18: Semiconductors - continued (Kittel Ch. 8) + a - Donors and acceptors J U,e e J q,e Transport of charge and energy h E J q,e J U,h Physics 460 F 2006 Lect 18 1 Outline More on concentrations
More information2) Atom manipulation. Xe / Ni(110) Model: Experiment:
2) Atom manipulation D. Eigler & E. Schweizer, Nature 344, 524 (1990) Xe / Ni(110) Model: Experiment: G.Meyer, et al. Applied Physics A 68, 125 (1999) First the tip is approached close to the adsorbate
More informationScanning probe microscopy of graphene with a CO terminated tip
Scanning probe microscopy of graphene with a CO terminated tip Andrea Donarini T. Hofmann, A. J. Weymouth, F. Gießibl 7.5.2014 - Theory Group Seminar The sample Single monolayer of graphene Epitaxial growth
More informationLecture 7: Extrinsic semiconductors - Fermi level
Lecture 7: Extrinsic semiconductors - Fermi level Contents 1 Dopant materials 1 2 E F in extrinsic semiconductors 5 3 Temperature dependence of carrier concentration 6 3.1 Low temperature regime (T < T
More informationPhysics of Semiconductors (Problems for report)
Physics of Semiconductors (Problems for report) Shingo Katsumoto Institute for Solid State Physics, University of Tokyo July, 0 Choose two from the following eight problems and solve them. I. Fundamentals
More informationDefense Technical Information Center Compilation Part Notice
UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADP012911 TITLE: Low Temperature Scanning Tunneling Spectroscopy of Different Individual Impurities on GaAs [110] Surface and in
More informationElectron spins in nonmagnetic semiconductors
Electron spins in nonmagnetic semiconductors Yuichiro K. Kato Institute of Engineering Innovation, The University of Tokyo Physics of non-interacting spins Optical spin injection and detection Spin manipulation
More informationBasic Semiconductor Physics
6 Basic Semiconductor Physics 6.1 Introduction With this chapter we start with the discussion of some important concepts from semiconductor physics, which are required to understand the operation of solar
More informationElectronic Structure of a Hydrogenic Acceptor Impurity in Semiconductor Nano-structures
Nanoscale Res Lett (7) 2:4 6 DOI.7/s67-7-998-9 NANO EXPRESS Electronic Structure of a Hydrogenic Acceptor Impurity in Semiconductor Nano-structures Shu-Shen Li Æ Jian-Bai Xia Received: 7 September 7 /
More informationThe Semiconductor in Equilibrium
Lecture 6 Semiconductor physics IV The Semiconductor in Equilibrium Equilibrium, or thermal equilibrium No external forces such as voltages, electric fields. Magnetic fields, or temperature gradients are
More informationLuttinger Liquid at the Edge of a Graphene Vacuum
Luttinger Liquid at the Edge of a Graphene Vacuum H.A. Fertig, Indiana University Luis Brey, CSIC, Madrid I. Introduction: Graphene Edge States (Non-Interacting) II. III. Quantum Hall Ferromagnetism and
More informationLuminescence basics. Slide # 1
Luminescence basics Types of luminescence Cathodoluminescence: Luminescence due to recombination of EHPs created by energetic electrons. Example: CL mapping system Photoluminescence: Luminescence due to
More informationScanning Tunneling Microscopy. how does STM work? the quantum mechanical picture example of images how can we understand what we see?
Scanning Tunneling Microscopy how does STM work? the quantum mechanical picture example of images how can we understand what we see? Observation of adatom diffusion with a field ion microscope Scanning
More informationSurfaces, Interfaces, and Layered Devices
Surfaces, Interfaces, and Layered Devices Building blocks for nanodevices! W. Pauli: God made solids, but surfaces were the work of Devil. Surfaces and Interfaces 1 Interface between a crystal and vacuum
More information2016 to date Associate Professor İzmir Institute of Technology, Department of Physics, İzmir, Turkey
Cem ÇELEBİ İzmir Institute of Technology (IZTECH) Department of Physics, 35430 Urla İzmir, TURKEY Work: +90 (0232) 750 7711 E-mail: cemcelebi@iyte.edu.tr Home page: http://qdl.iyte.edu.tr/ Employment 2016
More informationEECS143 Microfabrication Technology
EECS143 Microfabrication Technology Professor Ali Javey Introduction to Materials Lecture 1 Evolution of Devices Yesterday s Transistor (1947) Today s Transistor (2006) Why Semiconductors? Conductors e.g
More informationSTM spectroscopy (STS)
STM spectroscopy (STS) di dv 4 e ( E ev, r) ( E ) M S F T F Basic concepts of STS. With the feedback circuit open the variation of the tunneling current due to the application of a small oscillating voltage
More informationColumnar quantum dots (QD) in polarization insensitive SOA and non-radiative Auger processes in QD: a theoretical study
olumnar quantum dots (QD) in polarization insensitive SOA and non-radiative Auger processes in QD: a theoretical study J. Even, L. Pedesseau, F. Doré, S. Boyer-Richard, UMR FOTON 68 NRS, INSA de Rennes,
More informationZero- or two-dimensional?
Stacked layers of submonolayer InAs in GaAs: Zero- or two-dimensional? S. Harrison*, M. Young, M. Hayne, P. D. Hodgson, R. J. Young A. Schliwa, A. Strittmatter, A. Lenz, H. Eisele, U. W. Pohl, D. Bimberg
More informationExciton spectroscopy
Lehrstuhl Werkstoffe der Elektrotechnik Exciton spectroscopy in wide bandgap semiconductors Lehrstuhl Werkstoffe der Elektrotechnik (WW6), Universität Erlangen-Nürnberg, Martensstr. 7, 91058 Erlangen Vortrag
More informationInfluence of hyperfine interaction on optical orientation in self-assembled InAs/GaAs quantum dots
Influence of hyperfine interaction on optical orientation in self-assembled InAs/GaAs quantum dots O. Krebs, B. Eble (PhD), S. Laurent (PhD), K. Kowalik (PhD) A. Kudelski, A. Lemaître, and P. Voisin Laboratoire
More informationElectronic States of InAs/GaAs Quantum Dots by Scanning Tunneling Spectroscopy
Electronic States of InAs/GaAs Quantum Dots by Scanning Tunneling Spectroscopy S. Gaan, Guowei He, and R. M. Feenstra Dept. Physics, Carnegie Mellon University, Pittsburgh, PA 15213 J. Walker and E. Towe
More informationConserved Spin Quantity in Strained Hole Systems with Rashba and Dresselhaus Spin-Orbit Coupling
Conserved Spin Quantity in Strained Hole Systems with Rashba and Dresselhaus Spin-Orbit Coupling Paul Wenk, Michael Kammermeier, John Schliemann, Klaus Richter, Roland Winkler SFB Workshop Bernried 30.09.2014
More informationCMT. Excitons in self-assembled type- II quantum dots and coupled dots. Karen Janssens Milan Tadic Bart Partoens François Peeters
Excitons in self-assembled type- II quantum dots and coupled dots CMT Condensed Matter Theory Karen Janssens Milan Tadic Bart Partoens François Peeters Universiteit Antwerpen Self-assembled quantum dots
More informationSpatially resolving density-dependent screening around a single charged atom in graphene
Supplementary Information for Spatially resolving density-dependent screening around a single charged atom in graphene Dillon Wong, Fabiano Corsetti, Yang Wang, Victor W. Brar, Hsin-Zon Tsai, Qiong Wu,
More informationQUANTUM WELLS, WIRES AND DOTS
QUANTUM WELLS, WIRES AND DOTS Theoretical and Computational Physics of Semiconductor Nanostructures Second Edition Paul Harrison The University of Leeds, UK /Cf}\WILEY~ ^INTERSCIENCE JOHN WILEY & SONS,
More informationEECS130 Integrated Circuit Devices
EECS130 Integrated Circuit Devices Professor Ali Javey 8/30/2007 Semiconductor Fundamentals Lecture 2 Read: Chapters 1 and 2 Last Lecture: Energy Band Diagram Conduction band E c E g Band gap E v Valence
More informationAnomalous spin suscep.bility and suppressed exchange energy of 2D holes
Anomalous spin suscep.bility and suppressed exchange energy of 2D holes School of Chemical and Physical Sciences & MacDiarmid Ins7tute for Advanced Materials and Nanotechnology Victoria University of Wellington
More informationEnergy Spectrum and Broken spin-surface locking in Topological Insulator quantum dots
Energy Spectrum and Broken spin-surface locking in Topological Insulator quantum dots A. Kundu 1 1 Heinrich-Heine Universität Düsseldorf, Germany The Capri Spring School on Transport in Nanostructures
More informationUniversal valence-band picture of. the ferromagnetic semiconductor GaMnAs
Universal valence-band picture of the ferromagnetic semiconductor GaMnAs Shinobu Ohya *, Kenta Takata, and Masaaki Tanaka Department of Electrical Engineering and Information Systems, The University of
More informationKondo effect in multi-level and multi-valley quantum dots. Mikio Eto Faculty of Science and Technology, Keio University, Japan
Kondo effect in multi-level and multi-valley quantum dots Mikio Eto Faculty of Science and Technology, Keio University, Japan Outline 1. Introduction: next three slides for quantum dots 2. Kondo effect
More informationinterband transitions in semiconductors M. Fox, Optical Properties of Solids, Oxford Master Series in Condensed Matter Physics
interband transitions in semiconductors M. Fox, Optical Properties of Solids, Oxford Master Series in Condensed Matter Physics interband transitions in quantum wells Atomic wavefunction of carriers in
More informationQuantum Confinement in Graphene
Quantum Confinement in Graphene from quasi-localization to chaotic billards MMM dominikus kölbl 13.10.08 1 / 27 Outline some facts about graphene quasibound states in graphene numerical calculation of
More informationDensity of states for electrons and holes. Distribution function. Conduction and valence bands
Intrinsic Semiconductors In the field of semiconductors electrons and holes are usually referred to as free carriers, or simply carriers, because it is these particles which are responsible for carrying
More informationCh. 2: Energy Bands And Charge Carriers In Semiconductors
Ch. 2: Energy Bands And Charge Carriers In Semiconductors Discrete energy levels arise from balance of attraction force between electrons and nucleus and repulsion force between electrons each electron
More informationIntroduction to Optoelectronic Device Simulation by Joachim Piprek
NUSOD 5 Tutorial MA Introduction to Optoelectronic Device Simulation by Joachim Piprek Outline:. Introduction: VCSEL Example. Electron Energy Bands 3. Drift-Diffusion Model 4. Thermal Model 5. Gain/Absorption
More informationPhotonic devices for quantum information processing:
Outline Photonic devices for quantum information processing: coupling to dots, structure design and fabrication Optoelectronics Group, Cavendish Lab Outline Vuckovic s group Noda s group Outline Outline
More informationSTM spectra of graphene
STM spectra of graphene K. Sengupta Theoretical Physics Division, IACS, Kolkata. Collaborators G. Baskaran, I.M.Sc Chennai, K. Saha, IACS Kolkata I. Paul, Grenoble France H. Manoharan, Stanford USA Refs:
More informationInterstitial Mn in (Ga,Mn)As: Hybridization with Conduction Band and Electron Mediated Exchange Coupling
Vol. 112 (2007) ACTA PHYSICA POLONICA A No. 2 Proceedings of the XXXVI International School of Semiconducting Compounds, Jaszowiec 2007 Interstitial Mn in (Ga,Mn)As: Hybridization with Conduction Band
More informationEE143 Fall 2016 Microfabrication Technologies. Evolution of Devices
EE143 Fall 2016 Microfabrication Technologies Prof. Ming C. Wu wu@eecs.berkeley.edu 511 Sutardja Dai Hall (SDH) 1-1 Evolution of Devices Yesterday s Transistor (1947) Today s Transistor (2006) 1-2 1 Why
More informationLecture 3: Heterostructures, Quasielectric Fields, and Quantum Structures
Lecture 3: Heterostructures, Quasielectric Fields, and Quantum Structures MSE 6001, Semiconductor Materials Lectures Fall 2006 3 Semiconductor Heterostructures A semiconductor crystal made out of more
More informationCLASS 12th. Semiconductors
CLASS 12th Semiconductors 01. Distinction Between Metals, Insulators and Semi-Conductors Metals are good conductors of electricity, insulators do not conduct electricity, while the semiconductors have
More informationDEFECTS IN 2D MATERIALS: HOW WE TAUGHT ELECTRONIC SCREENING TO MACHINES
DEFECTS IN 2D MATERIALS: HOW WE TAUGHT ELECTRONIC SCREENING TO MACHINES Johannes Lischner Imperial College London LISCHNER GROUP AT IMPERIAL COLLEGE LONDON Theory and simulation of materials: focus on
More informationg-factors in quantum dots
g-factors in quantum dots Craig Pryor Dept. of Physics and Astronomy University of Iowa With: Michael Flatté, Joseph Pingenot, Amrit De supported by DARPA/ARO DAAD19-01-1-0490 g-factors in quantum dots
More informationElectron Energy, E E = 0. Free electron. 3s Band 2p Band Overlapping energy bands. 3p 3s 2p 2s. 2s Band. Electrons. 1s ATOM SOLID.
Electron Energy, E Free electron Vacuum level 3p 3s 2p 2s 2s Band 3s Band 2p Band Overlapping energy bands Electrons E = 0 1s ATOM 1s SOLID In a metal the various energy bands overlap to give a single
More informationStrain-Induced Band Profile of Stacked InAs/GaAs Quantum Dots
Engineering and Physical Sciences * Department of Physics, Faculty of Science, Ubon Ratchathani University, Warinchamrab, Ubon Ratchathani 490, Thailand ( * Corresponding author s e-mail: w.sukkabot@gmail.com)
More informationMicroscopy and Spectroscopy with Tunneling Electrons STM. Sfb Kolloquium 23rd October 2007
Microscopy and Spectroscopy with Tunneling Electrons STM Sfb Kolloquium 23rd October 2007 The Tunnel effect T ( E) exp( S Φ E ) Barrier width s Barrier heigth Development: The Inventors 1981 Development:
More informationVisualization of atomic-scale phenomena in superconductors
Visualization of atomic-scale phenomena in superconductors Andreas Kreisel, Brian Andersen Niels Bohr Institute, University of Copenhagen, 2100 København, Denmark Peayush Choubey, Peter Hirschfeld Department
More informationCrystal Properties. MS415 Lec. 2. High performance, high current. ZnO. GaN
Crystal Properties Crystal Lattices: Periodic arrangement of atoms Repeated unit cells (solid-state) Stuffing atoms into unit cells Determine mechanical & electrical properties High performance, high current
More informationSurfaces, Interfaces, and Layered Devices
Surfaces, Interfaces, and Layered Devices Building blocks for nanodevices! W. Pauli: God made solids, but surfaces were the work of Devil. Surfaces and Interfaces 1 Role of surface effects in mesoscopic
More informationBasic cell design. Si cell
Basic cell design Si cell 1 Concepts needed to describe photovoltaic device 1. energy bands in semiconductors: from bonds to bands 2. free carriers: holes and electrons, doping 3. electron and hole current:
More informationCHAPTER 2: ENERGY BANDS & CARRIER CONCENTRATION IN THERMAL EQUILIBRIUM. M.N.A. Halif & S.N. Sabki
CHAPTER 2: ENERGY BANDS & CARRIER CONCENTRATION IN THERMAL EQUILIBRIUM OUTLINE 2.1 INTRODUCTION: 2.1.1 Semiconductor Materials 2.1.2 Basic Crystal Structure 2.1.3 Basic Crystal Growth technique 2.1.4 Valence
More informationChapter 2. Theoretical background. 2.1 Itinerant ferromagnets and antiferromagnets
Chapter 2 Theoretical background The first part of this chapter gives an overview of the main static magnetic behavior of itinerant ferromagnetic and antiferromagnetic materials. The formation of the magnetic
More information3. Two-dimensional systems
3. Two-dimensional systems Image from IBM-Almaden 1 Introduction Type I: natural layered structures, e.g., graphite (with C nanostructures) Type II: artificial structures, heterojunctions Great technological
More informationZeeman splitting of single semiconductor impurities in resonant tunneling heterostructures
Superlattices and Microstructures, Vol. 2, No. 4, 1996 Zeeman splitting of single semiconductor impurities in resonant tunneling heterostructures M. R. Deshpande, J. W. Sleight, M. A. Reed, R. G. Wheeler
More information3.23 Electrical, Optical, and Magnetic Properties of Materials
MIT OpenCourseWare http://ocw.mit.edu 3.23 Electrical, Optical, and Magnetic Properties of Materials Fall 2007 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms.
More informationEnergy dispersion relations for holes inn silicon quantum wells and quantum wires
Purdue University Purdue e-pubs Other Nanotechnology Publications Birck Nanotechnology Center 6--7 Energy dispersion relations for holes inn silicon quantum wells and quantum wires Vladimir Mitin Nizami
More informationCross-Section Scanning Tunneling Microscopy of InAs/GaSb Superlattices
Cross-Section Scanning Tunneling Microscopy of InAs/GaSb Superlattices Cecile Saguy A. Raanan, E. Alagem and R. Brener Solid State Institute. Technion, Israel Institute of Technology, Haifa 32000.Israel
More informationIntroduction to Engineering Materials ENGR2000. Dr.Coates
Introduction to Engineering Materials ENGR2000 Chapter 18: Electrical Properties Dr.Coates 18.2 Ohm s Law V = IR where R is the resistance of the material, V is the voltage and I is the current. l R A
More informationExperimental methods in physics. Local probe microscopies I
Experimental methods in physics Local probe microscopies I Scanning tunnelling microscopy (STM) Jean-Marc Bonard Academic year 09-10 1. Scanning Tunneling Microscopy 1.1. Introduction Image of surface
More informationSpin and Charge transport in Ferromagnetic Graphene
Spin and Charge transport in Ferromagnetic Graphene Hosein Cheraghchi School of Physics, Damghan University Recent Progress in D Systems, Oct, 4, IPM Outline: Graphene Spintronics Background on graphene
More informationTopological edge states in a high-temperature superconductor FeSe/SrTiO 3 (001) film
Topological edge states in a high-temperature superconductor FeSe/SrTiO 3 (001) film Z. F. Wang 1,2,3+, Huimin Zhang 2,4+, Defa Liu 5, Chong Liu 2, Chenjia Tang 2, Canli Song 2, Yong Zhong 2, Junping Peng
More informationELEMENTARY BAND THEORY
ELEMENTARY BAND THEORY PHYSICIST Solid state band Valence band, VB Conduction band, CB Fermi energy, E F Bloch orbital, delocalized n-doping p-doping Band gap, E g Direct band gap Indirect band gap Phonon
More informationOutline. Introduction: graphene. Adsorption on graphene: - Chemisorption - Physisorption. Summary
Outline Introduction: graphene Adsorption on graphene: - Chemisorption - Physisorption Summary 1 Electronic band structure: Electronic properties K Γ M v F = 10 6 ms -1 = c/300 massless Dirac particles!
More informationTeaching Nanomagnets New Tricks
Teaching Nanomagnets New Tricks v / Igor Zutic R. Oszwaldowski, J. Pientka, J. Han, University at Buffalo, State University at New York A. Petukhov, South Dakota School Mines & Technology P. Stano, RIKEN
More informationElectronic Properties of Ultimate Nanowires. F. J. Himpsel, S. C. Erwin, I. Barke,
Electronic Properties of Ultimate Nanowires F. J. Himpsel, S. C. Erwin, I. Barke, Nanostructures with Atomic Precision Single-Atom Wire, Single Wave Function Ultimate Limits of Electronics, Data Storage
More informationOptical Properties of Lattice Vibrations
Optical Properties of Lattice Vibrations For a collection of classical charged Simple Harmonic Oscillators, the dielectric function is given by: Where N i is the number of oscillators with frequency ω
More informationLuminescence Process
Luminescence Process The absorption and the emission are related to each other and they are described by two terms which are complex conjugate of each other in the interaction Hamiltonian (H er ). In an
More informationObservation of Bulk Defects by Scanning Tunneling Microscopy and Spectroscopy: Arsenic Antisite Defects in GaAs
VOLUME 71, NUMBER 8 PH YSICAL REVI EW LETTERS 23 AUGUST 1993 Observation of Bulk Defects by Scanning Tunneling Microscopy and Spectroscopy: Arsenic Antisite Defects in GaAs R. M. Feenstra, J. M. Woodall,
More informationFYS Vår 2017 (Kondenserte fasers fysikk)
FYS3410 - Vår 2017 (Kondenserte fasers fysikk) http://www.uio.no/studier/emner/matnat/fys/fys3410/v16/index.html Pensum: Introduction to Solid State Physics by Charles Kittel (Chapters 1-9, 11, 17, 18,
More informationChapter 1 Overview of Semiconductor Materials and Physics
Chapter 1 Overview of Semiconductor Materials and Physics Professor Paul K. Chu Conductivity / Resistivity of Insulators, Semiconductors, and Conductors Semiconductor Elements Period II III IV V VI 2 B
More informationChapter 4: Bonding in Solids and Electronic Properties. Free electron theory
Chapter 4: Bonding in Solids and Electronic Properties Free electron theory Consider free electrons in a metal an electron gas. regards a metal as a box in which electrons are free to move. assumes nuclei
More informationLecture 4 (19/10/2012)
4B5: Nanotechnology & Quantum Phenomena Michaelmas term 2012 Dr C Durkan cd229@eng.cam.ac.uk www.eng.cam.ac.uk/~cd229/ Lecture 4 (19/10/2012) Boundary-value problems in Quantum Mechanics - 2 Bound states
More informationStudy of semiconductors with positrons. Outlook:
Study of semiconductors with positrons V. Bondarenko, R. Krause-Rehberg Martin-Luther-University Halle-Wittenberg, Halle, Germany Introduction Positron trapping into defects Methods of positron annihilation
More informationNovel materials and nanostructures for advanced optoelectronics
Novel materials and nanostructures for advanced optoelectronics Q. Zhuang, P. Carrington, M. Hayne, A Krier Physics Department, Lancaster University, UK u Brief introduction to Outline Lancaster University
More informationTopological Defects inside a Topological Band Insulator
Topological Defects inside a Topological Band Insulator Ashvin Vishwanath UC Berkeley Refs: Ran, Zhang A.V., Nature Physics 5, 289 (2009). Hosur, Ryu, AV arxiv: 0908.2691 Part 1: Outline A toy model of
More informationAtoms? All matters on earth made of atoms (made up of elements or combination of elements).
Chapter 1 Atoms? All matters on earth made of atoms (made up of elements or combination of elements). Atomic Structure Atom is the smallest particle of an element that can exist in a stable or independent
More informationIntroduction to Density Functional Theory with Applications to Graphene Branislav K. Nikolić
Introduction to Density Functional Theory with Applications to Graphene Branislav K. Nikolić Department of Physics and Astronomy, University of Delaware, Newark, DE 19716, U.S.A. http://wiki.physics.udel.edu/phys824
More informationarxiv: v1 [cond-mat.mtrl-sci] 16 Apr 2007
Bound hole states in a ferromagnetic (Ga,Mn)As environment arxiv:0704.2028v1 [cond-mat.mtrl-sci] 16 Apr 2007 M.J. Schmidt, 1,2 K. Pappert, 1 C. Gould, 1 G. Schmidt, 1 R. Oppermann, 2 and L.W. Molenkamp
More informationEnergy bands in solids. Some pictures are taken from Ashcroft and Mermin from Kittel from Mizutani and from several sources on the web.
Energy bands in solids Some pictures are taken from Ashcroft and Mermin from Kittel from Mizutani and from several sources on the web. we are starting to remind p E = = mv 1 2 = k mv = 2 2 k 2m 2 Some
More information* motif: a single or repeated design or color
Chapter 2. Structure A. Electronic structure vs. Geometric structure B. Clean surface vs. Adsorbate covered surface (substrate + overlayer) C. Adsorbate structure - how are the adsorbed molecules bound
More informationFabrication / Synthesis Techniques
Quantum Dots Physical properties Fabrication / Synthesis Techniques Applications Handbook of Nanoscience, Engineering, and Technology Ch.13.3 L. Kouwenhoven and C. Marcus, Physics World, June 1998, p.35
More informationRashba spin-orbit coupling in the oxide 2D structures: The KTaO 3 (001) Surface
Rashba spin-orbit coupling in the oxide 2D structures: The KTaO 3 (001) Surface Sashi Satpathy Department of Physics University of Missouri, Columbia, USA E Ref: K. V. Shanavas and S. Satpathy, Phys. Rev.
More informationELECTRONS AND PHONONS IN SEMICONDUCTOR MULTILAYERS
ELECTRONS AND PHONONS IN SEMICONDUCTOR MULTILAYERS Second Edition B.K. RIDLEY University of Essex CAMBRIDGE UNIVERSITY PRESS Contents Preface Introduction 1 Simple Models of the Electron-Phonon Interaction
More information1.1 Atoms. 1.1 Atoms
1. Chemical bonding and crystal structure 19 21 Hydrogen atom Scanning electron microscopy Ni surface Cleaved surface ZnO, TiO 2, NiO, NaCl, Si, Ge, GaAs, InP Crystals are build by small repeating units
More informationNumerical study of hydrogenic effective mass theory for an impurity P donor in Si in the presence of an electric field and interfaces
PHYSICAL REVIEW B 68, 075317 003 Numerical study of hydrogenic effective mass theory for an impurity P donor in Si in the presence of an electric field and interfaces L. M. Kettle, 1, H.-S. Goan, 3 Sean
More informationSpectroscopies for Unoccupied States = Electrons
Spectroscopies for Unoccupied States = Electrons Photoemission 1 Hole Inverse Photoemission 1 Electron Tunneling Spectroscopy 1 Electron/Hole Emission 1 Hole Absorption Will be discussed with core levels
More informationSpin Coherent Phenomena in Quantum Dots Driven by Magnetic Fields
Spin Coherent Phenomena in Quantum Dots Driven by Magnetic Fields Gloria Platero Instituto de Ciencia de Materiales (ICMM), CSIC, Madrid, Spain María Busl (ICMM), Rafael Sánchez,Université de Genève Toulouse,
More informationGraphite, graphene and relativistic electrons
Graphite, graphene and relativistic electrons Introduction Physics of E. graphene Y. Andrei Experiments Rutgers University Transport electric field effect Quantum Hall Effect chiral fermions STM Dirac
More informationElectronic Structure of Surfaces
Electronic Structure of Surfaces When solids made of an infinite number of atoms are formed, it is a common misconception to consider each atom individually. Rather, we must consider the structure of the
More informationLecture 8 January 24, 2013 GaAs crystal surfaces, n-p dopants Si
Lecture 8 January 24, 2013 Ga crystal surfaces, n-p dopants Si Nature of the Chemical Bond with applications to catalysis, materials science, nanotechnology, surface science, bioinornic chemistry, and
More informationDocument Version Publisher s PDF, also known as Version of Record (includes final page, issue and volume numbers)
Controlled charge switching on a single donor with a scanning tunneling microscope Teichmann, K.; Wenderoth, M.; Loth, S.; Ulbrich, R.G.; Garleff, J.K.; Wijnheijmer, A.P.; Koenraad, P.M. Published in:
More information