Electromagnetic effects induced by a time-dependent axion field
Electromagnetic effects induced by a time-dependent axion field
复制标题
DOI：
10.1103/physrevb.97.214409
复制
发表时间：
2018-06
影响因子：
3.7
通讯作者：
K. Taguchi;Tatsushi Imaeda;T. Hajiri;T. Shiraishi;Yukio Tanaka;N. Kitajima;T. Naka
中科院分区：
文献类型：
--
作者：
K. Taguchi;Tatsushi Imaeda;T. Hajiri;T. Shiraishi;Yukio Tanaka;N. Kitajima;T. Naka
我们研究了所谓的 $\theta$ 项的动力学，它存在于拓扑材料中，与 Peccei-Quinn 在粒子物理学中预测的假设场有关，在使用拓扑绝缘体和两个铁磁绝缘体构建的磁超晶格中，其中铁磁绝缘体具有垂直磁各向异性和不同的磁矫顽场。我们研究了一种通过使用外部磁场改变反演对称性（从反平行到平行磁配置）来驱动磁超晶格中 $\theta$ 项动力学的方法。结果，我们发现非常规电磁场（即磁场感应的充电电流，反之亦然）是由 $\theta$ 项的非零动力学产生的。
We studied the dynamics of the so-called $\theta$-term, which exists in topological materials and is related to a hypothetical field predicted by Peccei-Quinn in particle physics, in a magnetic superlattice constructed using a topological insulator and two ferromagnetic insulators, where the ferromagnetic insulators had perpendicular magnetic anisotropies and different magnetic coercive fields. We examined a way to drive the dynamics of the $\theta$-term in the magnetic superlattice through changing the inversion symmetry (from an anti-parallel to a parallel magnetic configuration) using an external magnetic field. As a result, we found that unconventional electromagnetic fields, which are magnetic field-induced charge currents and vice versa, are generated by the nonzero dynamics of the $\theta$-term.