Investigation of the room-temperature photoelectron spectroscopy of type-II Weyl semimetal candidate WTe2
Investigation of the room-temperature photoelectron spectroscopy of type-II Weyl semimetal candidate WTe2
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DOI：
10.1007/s42864-023-00209-1
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发表时间：
2023-03
期刊：
影响因子：
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通讯作者：
Jianlin Ding;Zhengtai Liu;Zhe Huang;Zhicheng Jiang;Yichen Yang;Zhong Liu;Jishan Liu;Yangbin Guo;Da-Wei Shen
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文献类型：
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作者：
Jianlin Ding;Zhengtai Liu;Zhe Huang;Zhicheng Jiang;Yichen Yang;Zhong Liu;Jishan Liu;Yangbin Guo;Da-Wei Shen
层状过渡金属二硫属化合物具有新颖的物理性质和巨大的应用潜力。其中，WTe 2，它具有极大的不饱和磁电阻，理论上预测是一个II型外尔半金属，已被广泛研究。本文利用高分辨角分辨光电子能谱（ARPES）系统地研究了室温下WTe 2的电子结构。我们发现，温度驱动的化学势移动和Lifshitz转变，这是相当于低能带结构向下移动约50 meV，在低温下的结果相比。我们的ARPES实验结果与以前的理论计算相吻合，暗示了在Γ-X轴附近可能存在II型Weyl点.同时，正如所预期的，存在一个主要的电子类费米面，而不是一个具有补偿电子和空穴。同时，我们的ARPES结果表明，在室温下，位于费米能级（EF）以下的平带（FB）变得更接近费米能级，这可能开始主导输运行为，导致不饱和巨磁电阻效应的消失.这些发现不仅揭示了WTe 2在室温下的电子结构特征，而且为室温拓扑量子器件的发展提供了新的思路.
Layered transition metal dichalcogenides have novel physical properties and great potential for applications. Among them, WTe2, which has an extremely large unsaturated magnetoresistance and is theoretically predicted to be a type-II Weyl semimetal, has been extensively studied. Here, we systematically probe the electronic structure of WTe2at room temperature using high-resolution angle-resolved photoelectron spectroscopy (ARPES). We find that temperature-driven chemical potential shift and Lifshitz transition, which is equivalent to low-energy band structures shift downward by around 50 meV, compared to the results at low temperatures. Our ARPES experimental results match well with previous theoretical calculations, implying the possible existence of type-II Weyl points near the Γ-Xaxis. Also, as expected, there exists a dominantly electron-like Fermi surface instead of the one with compensated electrons and holes. Meanwhile, our ARPES results show that the flat band (FB) lying below the Fermi level (EF) becomes closer to the Fermi level at room temperature, which might start to dominate the transport behavior and lead to the disappearance of the unsaturated giant magnetoresistance effect. These findings not only reveal the electronic structure features of WTe2at room temperature, but also provide new insights into the development of room-temperature topological quantum devices.