过渡金属二氧化TaAs中的电子结构2
Sabin Regmi1,2, Cheng-Yi Huang3, Mojammel A Khan4
1Department of Physics, University of Central Florida, Orlando, FL 32816, United States of America.
概括
研究人员调查了TaAs2,揭示了金属费米表面口袋和线性带. 开放费米表面特征可能有助于其极端磁阻 (MR),尽管缺乏拓表面状态.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
- 拓学材料 拓学材料
背景情况:
- 过渡金属二化物已知具有拓状态和很大的磁阻 (MR).
- 二二 (TaAs2) 理论上预测显示出一个拓晶体绝缘状态.
研究的目的:
- 实验性地研究TaAs2.2的电子结构和传输特性.
- 为了确定TaAs2.2中的极端电磁阻的起源.
- 为了澄清TaAs2表面的拓性质.
主要方法:
- 高分辨率的角度分辨率光辐射光谱 (ARPES) 探测费米表面 (FS) 和电子频段.
- 磁传输测量用于观察磁阻.
- 第一原则电子结构计算用于与实验数据进行比较.
主要成果:
- 在TaAs2.2的金属费米表面中,ARPES揭示了封闭和开放的口袋.
- 在 (2 ̅01) 表面上观察到线性分散带.
- 通过运输测量证实了极端电磁阻.
- 观察到的表面带被确定为微不足道的散装带,表明一个拓暗 (2 ̅01) 表面.
结论:
- TaAs2 的 (2 ̅01) 表面不容纳对称性保护的拓表面状态.
- 开放的费米表面口袋的存在是导致观察到的极端电磁阻的一个关键因素.
- TaAs2为研究费米表面拓与大磁阻之间的相互作用提供了一个有趣的平台.
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