Ultrafast Hot Carrier Dynamics Of Zrte5 From Time-Resolved Optical Reflectivity

ZrTe5 is a layered pentatelluride with very weak interlayer coupling, high in-plane carrier mobility, and strong electron-electron interaction. We investigate the hot carrier dynamics of ZrTe5 by ultrafast time-resolved optical reflectivity. Our results reveal a phonon-mediated across-gap recombination and an electron-phonon scattering channel in thermalization, with timescales of few and sub-ps, respectively. In addition we find a fast relaxation right after the initial photoexcitation with a time constant of similar to 250 fs, possibly arising from an electron-electron scattering channel. Our findings indicate that correlated many-body effects play an important role for the transient dynamics of ZrTe5.