Dynamics of out-of-equilibrium electron and hole pockets in the type-II Weyl semimetal candidate WTe2
Dynamics of out-of-equilibrium electron and hole pockets in the type-II Weyl semimetal candidate WTe2
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DOI：
10.1103/physrevb.97.115115
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发表时间：
2018-03-08
影响因子：
3.7
通讯作者：
Marsi, M.
中科院分区：
文献类型：
--
作者：
Caputo, M.;Khalil, L.;Marsi, M.
我们提出了一个时间和角度分辨的光发射研究过渡金属二硫族化合物WTe2，一个候选的ii型Weyl半金属具有极大的磁电阻。利用飞秒光脉冲，我们描述了费米能级以上电子口袋的未占据状态。在布里渊带不同部分的超快载流子弛豫之后，我们报告了电子和空穴非常相似的衰变动力学。我们的研究结果证实，电子和空穴之间的电荷补偿——解释这种材料的不饱和磁电阻的关键效应——是WTe2的一个显著特征，即使在非平衡状态下也是如此。
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.