发表机构
Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology; Institut für Theorie der Kondensierten Materie, Karlsruhe Institute of Technology; Department of Physics and Astronomy, Ohio University（卡尔斯鲁厄理工学院量子材料与技术研究所; 卡尔斯鲁厄理工学院凝聚态理论研究所; 俄亥俄大学物理与天文学系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究具有面内塞曼场和δ相关标量无序的二维Rashba薄膜直流电导率，发现场虽改变费米轮廓和自旋纹理，但准经典电导率中无各向异性磁阻，其机制是几何的，相关结果解决了短程无序准经典问题。
AI 中文摘要
我们研究了具有面内塞曼场和δ相关标量无序的连续二维Rashba薄膜的直流电导率。尽管该场使两个螺旋度费米轮廓变形并旋转自旋纹理，但在主导的准经典电导率中它不会产生各向异性磁阻。其机制是几何的。一个密度沃德恒等式将玻恩自能的自旋矢量部分固定为总粒子密度相对于场的导数。该导数消失，因为两个Rashba - 塞曼片所包围的总面积与面内场无关。因此，玻恩自能是标量且与场无关，准粒子寿命保持各向同性。相同的面积不变性控制输运：一旦主导的杂质阶梯将电流顶点简化为抛物线速度，对角带内库博电导率就会坍缩到两片占据区域上并且也与场无关。该结果解决了短程无序准经典问题：点状非磁性杂质在该模型中不会产生各向异性磁阻。非零的各向异性磁阻需要超出这种准经典短程无序机制的物理。
英文摘要
We study the dc conductivity of a two-dimensional Rashba system with an in-plane Zeeman field and delta-correlated scalar disorder. We show that, although the field deforms the two helicity Fermi contours and rotates the spin texture, it does not produce anisotropic magnetoresistance in the leading quasiclassical conductivity. The result follows from a geometric identity for the total area occupied by the two helicity sheets. A density Ward identity fixes the spin-vector part of the Born self-energy to the derivative of the total particle density with respect to the field. This derivative vanishes, because the total area enclosed by the two Rashba-Zeeman sheets is independent of the in-plane field. The Born self-energy is therefore scalar and field independent, and the quasiparticle lifetime stays isotropic. The same occupied-area identity controls transport: the leading impurity ladder reduces the current vertex to the parabolic velocity, and the diagonal intraband Kubo conductivity collapses onto the two-sheet occupied area and is field independent as well. Thus, point-like nonmagnetic impurities produce neither angular anisotropy nor field-magnitude dependence in the leading diagonal two-sheet quasiclassical conductivity. Any residual AMR from delta-correlated disorder must originate from corrections outside this sector.
Comments14 pages of main text, 8 pages of Supplementary information, 2 Figures; Extended version
