Berry连接和曲率
材料科学
霍尔效应
非线性系统
偶极子
曲率
浆果
凝聚态物理
几何学
物理
量子力学
数学
电阻率和电导率
植物
生物
几何相位
作者
Hongsheng Pang,Gan Jin,Lixin He
出处
期刊:Physical Review Materials
[American Physical Society]
日期:2024-04-16
卷期号:8 (4)
标识
DOI:10.1103/physrevmaterials.8.043403
摘要
In materials without inversion symmetry, the Berry curvature dipole (BCD) arises from the uneven distribution of Berry curvature in momentum space. This leads to nonlinear anomalous Hall effects even in systems with preserved time-reversal symmetry. A key goal is to engineer systems with prominent BCD near the Fermi level. Notably, TaAs, a type-I Weyl semimetal, exhibits substantial Berry curvature but a small BCD around the Fermi level. In this study, we employ first-principles methods to comprehensively investigate the BCD in TaAs. Our findings reveal significant cancellation effects not only within individual Weyl points, but crucially, among distinct Weyl point pairs in bulk TaAs. We propose a strategic approach to enhance the BCD in TaAs by employing a layer-stacking technique. This greatly amplifies the BCD compared to the bulk material. By tuning the number of slab layers, we can selectively target specific Weyl point pairs near the Fermi level, while quantum confinement effects suppress contributions from other pairs, mitigating cancellation effects. Specifically, the BCD of an eight-layer TaAs slab surpasses the bulk value near the Fermi level by orders of magnitude.
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