论文标题
极化跳跃通过打破二维Weyl半法的对称性
Polarization jumps by breaking symmetries of two-dimensional Weyl semimetals
论文作者
论文摘要
电偏光作为大量数量是由绝缘系统极化理论描述的，在导电系统中无法定义。在系统中参数逐渐变化时，只要差距保持开放，极化总是会平稳。在本文中，我们专注于二维Weyl半学，该二维Weyl semits托有受对称性保护的Weyl节点，并在引入对称性的$ M $ $ M $并打开间隙时研究极化的行为。我们表明，可以在$ m \ to0^+$和$ m \ to0^ - $ limits之间有一个跳跃。我们发现跳跃是由``Weyl Dipole''普遍描述的，该''Weyl偶极子代表了如何在互惠空间中取代具有单极电荷的Weyl节点。我们的结果适用于一般的二维Weyl半度。
The electric polarization as a bulk quantity is described by the modern theory of polarization in insulating systems and cannot be defined in conducting systems. Upon a gradual change of a parameter in the system, the polarization always varies smoothly as long as the gap remains open. In this paper, we focus on the two-dimensional Weyl semimetal, which hosts Weyl nodes protected by symmetries, and study the behavior of the polarization when a symmetry-breaking term $M$ is introduced and a gap opens. We show that there can be a jump between $M\to0^+$ and $M\to0^-$ limits. We find that the jump is universally described by the ``Weyl dipole" representing how the Weyl nodes with monopole charges are displaced in the reciprocal space. Our result is applicable to general two-dimensional Weyl semimetals.
