Electron-hole balanced dynamics in the type-II Weyl semimetal candidate WTe2

Abstract

We present a time- and angular-resolved photoemission (TR-ARPES) study of the transition- metal dichalcogenide WTe2, a candidate type II Weyl semimetal exhibiting extremely large magne- toresistence. Using femtosecond light pulses, we characterize the unoccupied states of the electron pockets above the Fermi level. We track the relaxation dynamics of photoexcited electrons along the unoccupied band structure and into a bulk hole pocket. Following the ultrafast carrier relaxation, we report remarkably similar decay dynamics for electrons and holes. Our results corroborate the hypothesis that carrier compensation is a key factor in the exceptional magnetotransport properties of WTe2.