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arXiv · 2303.14635

Kerr, Faraday, and Magnetoelectric Effects in MnBi$_2$Te$_4$ Thin Films

Chao Lei·Allan H. MacDonald
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Abstract

The topological magneto-electric effect (TME) is a characteristic property of topological insulators. In this article, we use a simplified coupled-Dirac-cone electronic structure model to theoretically evaluate the THz and far infrared Kerr and Faraday responses of thin films of MnBi$_2$Te$_4$ with up to $N=10$ septuple layers with the goal of clarifying the relationship between these convenient magneto-optical observables and the TME. We find that for even $N$ the linear Kerr and Faraday responses to an electric field vanish in the low-frequency limit, even though the magnetoelectric response is large and approximately quantized.

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Chao Lei, Allan H. MacDonald. 2023-03-26. Kerr, Faraday, and Magnetoelectric Effects in MnBi$_2$Te$_4$ Thin Films. https://doi.org/10.1103/physrevb.108.125424

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