谷密度的不保存及其对观测谷厅效应的影响
Alexander Kazantsev1, Amelia Mills1, Eoin O'Neill1
1Department of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom.
Physical review letters
|March 22, 2024
概括
尽管有大量电流,但在完全缺口的绝缘体中无法观察到山谷霍尔效应. 谷密度积累在间隙系统中是可能的,对于边缘极化来说,有了新的公式.
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
- 固态物理 固态物理
背景情况:
- 谷霍尔效应 (VHE) 是电子材料中的一种现象,其中具有不同谷指数的电荷载体分离.
- 保持谷密度是理解绝缘体中VHE的一个关键假设.
- 观测VHE通常依赖于检测系统边缘的山谷密度积累.
研究的目的:
- 研究电场对多谷隔热器中谷密度保护的影响.
- 为了确定在哪些条件下可以观察到山谷霍尔效应或是不可检测的.
- 导出一个理论框架,用于谷密度积累在间隙系统.
主要方法:
- 在驱动VHE的电场下的山谷密度保存的理论分析.
- 作为费米表面平均值的山谷密度积累的明确公式的推导.
- 该理论应用于一个有间隙的石墨烯纳米带模型系统.
主要成果:
- 驱动VHE的电场意外地打破了完全缺口绝缘体中的谷密度保护.
- 完全有间隙的时间逆转不变绝缘器可以在没有边缘积累的情况下呈现大量VHE电流,使VHE无法观察.
- 谷谷密度积累在非完全间隙系统中是可能的,仅来自上方间隙状态的贡献.
- 一个净谷密度极化是动态生成的特定边缘终端在间隙的石墨烯纳米带.
结论:
- 在完全缺口的绝缘体中,由于破谷密度保护,VHE无法观察到.
- 衍生式提供了一种新的方法来计算谷密度积累在隙材料.
- 动态谷极化可以发生在边缘,为valleytronics研究提供新的途径.
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