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

摘要: A major challenge in understanding the cuprate superconductors is to clarify nature of fundamental electronic correlations that lead pseudogap phenomenon. Here we use ultrashort light pulses prepare a non-thermal distribution excitations and capture novel properties are hidden at equilibrium. Using broadband (0.5–2 eV) probe, able track dynamics dielectric function unveil an anomalous decrease scattering rate charge carriers pseudogap-like region temperature (T) hole-doping (p) phase diagram. In this region, delimited by well-defined T*neq(p) line, photoexcitation process triggers evolution antinodal from gapped (localized) delocalized quasiparticles characterized longer lifetime. The concept photo-enhanced conductivity naturally explained within singleband Hubbard model, which short-range Coulomb repulsion leads k-space differentiation between nodal excitations.