# Magnetic-Resonance-Induced Pseudo-electric Field and Giant Current Response in Axion Insulators

## TL;DR

This paper proposes that dynamical magnetization in axion insulators generates a pseudo-electric field, producing a large measurable current at magnetic resonance, providing a practical way to confirm the axion insulator phase experimentally.

## Contribution

It introduces the concept of a pseudo-electric field induced by magnetization dynamics as a new method to detect axion insulators, with significantly enhanced current signals.

## Key findings

- Current at magnetic resonance exceeds topological magnetoelectric effect by orders of magnitude.
- Pseudo-electric field effectively induces measurable response current.
- Proposes a feasible experimental signature for axion insulator phase.

## Abstract

A quantized version of the magnetoelectric effect, known as the topological magnetoelectric effect, can exist in a time-reversal invariant topological insulator with all its surface states gapped out by magnetism. This topological phase, called the axion insulator phase, has been theoretically proposed but is still lack of conclusive experimental evidence due to the small signal of topological magnetoelectric effect. In this work, we propose that the dynamical in-plane magnetization in an axion insulator can generate a "pseudo-electric field", which acts on the surface state of topological insulator films and leads to the non-zero response current. Strikingly, we find that the current at magnetic resonance (either ferromagnetic or anti-ferromagnetic) is larger than that of topological magnetoelectric effect by several orders of magnitude, and thereby serves as a feasible smoking gun to confirm the axion insulator phase in the candidate materials.