Dynamics of out-of-equilibrium electron and hole pockets in the type-II Weyl semimetal candidate WTe2

Abstract

© 2018 American Physical Society. We present a time- and angle-resolved photoemission study of the transition-metal dichalcogenide WTe2, a candidate type-II Weyl semimetal exhibiting extremely large magnetoresistence. Using femtosecond light pulses, we characterize the unoccupied states of the electron pockets above the Fermi level. Following the ultrafast carrier relaxation in distinct parts of the Brillouin zone, we report remarkably similar decay dynamics for electrons and holes. Our results confirm that charge compensation between electron and hole pockets - a key effect to explain the nonsaturating magnetoresistance of this material - is a distinctive feature of WTe2 even in an out-of-equilibrium regime.