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arXiv · 1806.01548

Electromagnetic effects induced by time-dependent axion field

Katsuhisa Taguchi·Tatsushi Imaeda·Tetsuya Hajiri·Takuya Shiraishi·Yukio Tanaka·Naoya Kitajima·Tatsuhiro Naka
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Abstract

We studied the dynamics of the so-called $θ$-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 $θ$-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 $θ$-term.

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Katsuhisa Taguchi, Tatsushi Imaeda, Tetsuya Hajiri, Takuya Shiraishi, Yukio Tanaka, Naoya Kitajima, Tatsuhiro Naka. 2018-06-05. Electromagnetic effects induced by time-dependent axion field. https://doi.org/10.1103/physrevb.97.214409

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