Photo-enhanced antinodal conductivity in the pseudogap state of high T c cuprates

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1 SCSR 1 Trieste, Italy 11 December 1 Photo-enhanced antinodal conductivity in the pseudogap state of high T c cuprates Federico Cilento T-ReX Laboratory Elettra Sincrotrone Trieste, Trieste

2 The Pseudogap and the Phase Diagram Motivations: Determine the phase diagram Understanding PG formation Mottness?? Long range orders?? Key role of Non-Equilibrium Approach Lee, Nature 5, 81 (7) Damascelli, RMP 75, 73 (3)

3 The Pseudogap Is the Pseudogap related to the onset of long-range-orders? CDW, SDW, NEMATIC, STRIPES, MAGNETIC YBCO Nematic YBCO Stripes YBCO Magnetic YBCO Kerr Daou, Nature (1) Baek, PRB (1) Fauque, PRL (6) Xia, PRL (8) YBCO CDW BSCCO Stripes BSCCO Magnetic HBCO Magnetic Ghiringhelli, Science (1) Parker, Nature (1) De Almeida, PRB (1) Li, Nature (1) Dependence on the details of structure

Is it a phenomenon due to the short-range-correlations (Mottness)? Outcome from Hubbard Model solved by CDMFT (Columbia, Rutgers, Ecole Polytechnique, Sissa) Sordi, Sci. Rep.

4 Is it a phenomenon due to the short-range-correlations (Mottness)? Outcome from Hubbard Model solved by CDMFT (Columbia, Rutgers, Ecole Polytechnique, Sissa) Sordi, Sci. Rep. (1) T* delimits different dynamical regimes, indicating thermodynamic anomalies Widom line No broken symmetries are invoked Indication for Mottness in the PG No experimental evidences exists that confirm this indication There are general and common trends Barisic, PNAS (13) r per Cu-O sheet Resistivity HBCO YBCO LSCO TBCO The departure from the T-linear behavior occurs at the same temperature, T*, for different compounds.

Non-Equilibrium Approach & Time-Resolved Optical Spectroscopy DR/R(,t=t ) Energy (ev) Energy (ev) PUMP PROBE Dt Detector Photons Electrons ~1 fs pulses Sample

8 spectral fingerprint AND timescale. 1.8 -. -.6 -.8-1.x1-3 -1 * Study the effect of a small 1.6non-equilibrium distribution 1.6 * Framework: Differential 1.

5 Non-Equilibrium Approach & Time-Resolved Optical Spectroscopy DR/R(,t=t ) Energy (ev) Energy (ev) PUMP PROBE Dt Detector Photons Electrons ~1 fs pulses Sample Timescale BROADBAND PROBE Spectral Fingerprint. -.. * True spectroscopy with temporal resolution DR/R(,t) * Disentangle effects by their 1.8 spectral fingerprint AND timescale x * Study the effect of a small 1.6non-equilibrium distribution 1.6 * Framework: Differential 1. (variational) dielectric function approach 1. t Establish a 1:1 connection between spectral 1. fingerprint and its cause at the microscopic level x DR/R( =,t)

6 Isosbestic points and Reflectivity: R( ) R/R( ) How to measure the electronic scattering rate at high photon energies R( ), Drude Model 5 fs fs (-%) 6 fs (+%).. R/R( ) 5 fs --> fs 5 fs --> 6 fs ω 1. Energy (ev) ω.8 Energy (ev) Non-equilibrium optics with spectral resolution can provide access to both energy&momentum conserving scattering processes and electronic scattering rate. ε D ω = ε ω p ω + iγω R ω = 1 ε ω 1 + ε ω ω~ω: δr ω, γ = R γ (ω)δγ

7 R( ) Equilibrium and Non-Equilibrium optical spectroscopic data R/R(,t) R/R(,t) Optimally Doped Bi Sr Ca.9 Y.8 Cu O 8+δ (T c =96 K) Equilibrium Out-of-Equilibrium T=1 K 1 t=1 fs -1 -x1-3

8 Modeling non-equilibrium optical properties R/R R/R R/R 1 Y-Bi1 OP T=1 K 1 R/R at t=3 ps Fit Y-Bi1 OP T=1 K -1 -x1 - g> -1 -x1-3 R/R at t=1 fs Fit Gap Filling Reduced Scattering Rate.8 1. Energy (ev) 1.6 g< Energy (ev) 1.6 t < 1 ps: g < transient decrease of scattering rate (impulsive effect) x1 - R/R at 1.55 ev t > 3 ps: g > transient increase of scattering rate (thermal effect) 1 3

ARPES at Equilibrium and Out-of-Equilibrium I (a.u.) t (ps) ARPES at Equilibrium ARPES Out-of-Equilibrium.6.5. =18 =37 =7 =5 DI /I.3..1. 1 3 5. 1. hn=1. ev T=1 K.

9 ARPES at Equilibrium and Out-of-Equilibrium I (a.u.) t (ps) ARPES at Equilibrium ARPES Out-of-Equilibrium.6.5. =18 =37 =7 =5 DI /I hn=1. ev T=1 K..5 Equilibrium: A. Damascelli, UBC, Vancouver.. Non-Equilibrium: U. Bovensiepen, Duisburg F.S. Angle ( ) F.S. Angle ( ) hn=6 ev T=1 K Pump=1.5 ev, 3 mj/cm 5

10 Onset of the Pseudogap: T*=T*(p) from T-Scan Y-Bi1 Crystals with different doping level T T= K T=165 K T T*(p) line SC p Temperature scan at 1.55 ev probe photon energy

11 Universal Phase Diagram Temperature (K) Temperature (K) 1 3 Y-Bi1: T c,max =96 K, CuO planes per U.C. Hg11: T c,max =96 K, 1 CuO plane per U.C. YBi1 OD T c =83 K, p= K.E. gain. YBi1 UD T c =88 K, p=.13 Transient reduction scattering rate Doping YBi1 OPYBi1 Non-eq. T c =96 Hg11 K, p=.16 Non-eq. Hg11 K.E. loss T mag T c R/Rx T r T stripes T RUS (YBCO) T CDW (YBCO) T Kerr (YBCO).3 35 YBi1 OD T c =83 K, p= F. Cilento et al., Nat. Comm. 5, 353 (1) and arxiv T*(p) Line Hg11: T*(p=.15)=7 K T c =96 K Y-Bi1: T*(p=.13)= K T c =88 K T*(p=.16)=165 K T c =96 K T*(p=.18)=11 K T c =9 K.

12 Hubbard Hamiltonian and CDMFT H = t ij ciσ cjσ + c. c. + U n i, n i, μ n i i,j,σ UD (p=.5) i M. Capone - SISSA OD (p=.) i N -.3 N k y (Å -1 ) k x (Å -1 ) AN k y (Å -1 ) k x (Å -1 ) AN

13 The N-AN Dichotomy in the Pseudogap Nodal (N) and Antinodal (AN) scatering rate for UD and OD compounds M. Capone - SISSA The electronic scattering rate as a measure of the degree of electronic correlations The absorption of the pump pulse renders the AN quasiparticles more metallic, less localized

14 The Phase Diagram Temperature (K) Temperature (K) 35 3 YBi1 UD T c =88 K, p=.13 YBi1 OPNon-eq. T c =96 Hg11 K, p=.16 Non-eq. T mag 35 YBi1 OD T c =83 K, p=. 3 5 T r T stripes T RUS (YBCO) T CDW (YBCO) T Kerr (YBCO) Correlationdriven AN Mottness K.E. gain.15 Doping K.E. loss R/Rx Non equilibrium measurements reveal the Mottness associated to AN quasiparticles. Broken symmetries seem not to be related to the PG: are a consequence and not its cause.

15 Pseudogap and Ordering Tendencies Adapted by C. Giannetti W. S. Lee et al., Nature 5, 81 (7) R. Comin et al., Science 33, 39 (1) Q CO ~.56 r.l.u. (REXS/STM) Q HS ~.55 r.l.u. (ARPES)

16 Conclusions We revealed the fingerprint of Mottness for AN quasiparticles. The onset of the Mottness follows the T*(p) line. CDMFT simulations account for experimental results. The pseudogap phase is due to strong and short-ranged electronic correlations. Long-range orders are an effect of the Pseudogap, not its cause.

17 People, Collaborations, Acknowledgements Ultrafast optics group (Università degli Studi di Trieste and Elettra/Fermi) F. Cilento, A. Crepaldi, M. Zacchigna, G. Manzoni, A. Sterzi, G. Coslovich, F. Parmigiani Ultrafast optics group (Università Cattolica, Brescia) S. Dal Conte, D. Bossini, S. Peli, N. Nembrini, S. Mor, F. Banfi, G. Ferrini, C. Giannetti Equilibrium optical properties of HTSC D. van der Marel (Université de Genève) Equilibrium ARPES of HTSC R. Comin, A. Damascelli (University of British Columbia, Vancouver) Non-Equilibrium ARPES of HTSC L. Rettig, U. Bovensiepen (University of Duisburg) Non-equilibrium models of correlated materials M. Capone, M. Fabrizio (SISSA, Trieste) Samples A. Damascelli (University of British Columbia, Vancouver) M. Greven (University of Minnesota & Stanford University) H. Eisaki (NIST, Tsukuba, Japan)

Witnessing quasi-particle dynamics in strongly correlated electron system

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