论文标题
电流诱导的轨道磁化系统中没有反转对称的系统
Current-induced orbital magnetization in systems without inversion symmetry
论文作者
论文摘要
在具有时间反转对称性的系统中，轨道磁化的平衡为零。最近，已经提出，轨道磁化强度可以由螺旋晶体结构中的电流诱导，其方式与经典螺线管中的电流相同。在本文中，我们扩展了这一理论，并研究了无反转对称性的更广泛的系统中电流诱导的轨道磁化。首先，我们考虑没有反演对称性的极性金属。我们发现，即使没有自旋轨道偶联，电流诱导的轨道磁化也出现在垂直于电流的方向上。使用扰动方法，我们从物理上阐明了电流诱导的轨道磁化如何在极地金属中出现。例如，我们计算了SNP中电流诱导的轨道磁化，并发现它可能足够大以进行测量。接下来，我们考虑一个二维系统，而无需反转对称。我们建立了一种方法，通过在厚度方向上使用真实空间坐标来计算平面内部的电流诱导的轨道磁化。通过将该理论应用于绝缘体的表面和界面，我们发现沿表面和接口的电流会诱导垂直于电流的轨道磁化。
In systems with time-reversal symmetry, the orbital magnetization is zero in equilibrium. Recently, it has been proposed that the orbital magnetization can be induced by an electric current in a helical crystal structure in the same manner as that in a classical solenoid. In this paper, we extend this theory and study the current-induced orbital magnetization in a broader class of systems without inversion symmetry. First, we consider polar metals which have no inversion symmetry. We find that the current-induced orbital magnetization appears in a direction perpendicular to the electric current even without spin-orbit coupling. Using the perturbation method, we physically clarify how the current-induced orbital magnetization appears in polar metals. As an example, we calculate the current-induced orbital magnetization in SnP, and find that it might be sufficiently large for measurement. Next, we consider a two-dimensional system without inversion symmetry. We establish a method to calculate the current-induced orbital magnetization in the in-plane direction by using real-space coordinates in the thickness direction. By applying this theory to surfaces and interfaces of insulators, we find that an electric current along surfaces and interfaces induces an orbital magnetization perpendicular to the electric current.
