Temperature effect on lattice and electronic structures of WTe2 from first-principles study
Temperature effect on lattice and electronic structures of WTe2 from first-principles study
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第一性原理研究中温度对 WTe2 晶格和电子结构的影响
DOI：
10.1063/1.4974946
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发表时间：
2017-01-28
影响因子：
3.2
通讯作者：
Wan, Xiangang
中科院分区：
文献类型：
--
作者：
Liu, Gang;Liu, Huimei;Wan, Xiangang
二碲化钨（WTe2）具有极大的不饱和磁电阻（MR）。由于Te-5p和W-5d轨道的大空间延伸，WTe2的电子性质对晶格结构很敏感，这可能会影响实验中发现的强温度依赖性MR。基于第一性原理计算，我们研究了温度对WTe2晶格和电子结构的影响。数值结果表明，WTe2的热膨胀系数具有高度的各向异性，且相当大。然而，温度（小于300 K）对WTe2费米表面的影响可以忽略不计。我们的理论结果澄清了热膨胀不是温度引起磁阻快速下降的主要原因。
Tungsten ditelluride (WTe2) exhibits extremely large and unsaturated magnetoresistance (MR). Due to the large spatial extensions of Te-5p and W-5d orbitals, the electronic properties of WTe2 are sensitive to the lattice structures, which can probably affect the strongly temperature dependent MR found in the experiment. Based on first-principle calculations, we investigate the temperature effect on the lattice and electronic structures of WTe2. Our numerical results show that the thermal expansion coefficients of WTe2 are highly anisotropic and considerably large. However, the temperature (less than 300 K) has an ignorable effect on the Fermi surface of WTe2. Our theoretical results clarify that the thermal expansion is not the main reason for the temperature-induced rapid decrease of magnetoresistance.