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arXiv · 1911.01896

In-plane antiferromagnetic moments in axion topological insulator candidate EuIn$_2$As$_2$

Yang Zhang·Ke Deng·Xiao Zhang·Meng Wang·Yuan Wang·Cai Liu·Jia-Wei Mei·Shiv Kumar·Eike F. Schwier·Kenya Shimada·Chaoyu Chen·Bing Shen
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Abstract

Topological insulator with antiferromagnetic order can serve as an ideal platform for the realization of axion electrodynamics. In this paper, we report a systematic study of the axion topological insulator candidate EuIn$_2$As$_2$. A linear energy dispersion across the Fermi level confirms the existence of the proposed hole-type Fermi pocket. Spin-flop transitions occur with magnetic fields applied within the $ab$-plane while are absent for fields parallel to the $c$-axis. Anisotropic magnetic phase diagrams are observed and the orientation of the ground magnetic moment is found to be within the $ab$-plane. The magnetoresistivity for EuIn$_2$As$_2$ behaves non-monotonic as a function of field strength. It exhibits angular dependent evolving due to field-driven and temperature-driven magnetic states. These results indicate that the magnetic states of EuIn$_2$As$_2$ strongly affect the transport properties as well as the topological nature.

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Yang Zhang, Ke Deng, Xiao Zhang, Meng Wang, Yuan Wang, Cai Liu, Jia-Wei Mei, Shiv Kumar, Eike F. Schwier, Kenya Shimada, Chaoyu Chen, Bing Shen. 2019-11-05. In-plane antiferromagnetic moments in axion topological insulator candidate EuIn$_2$As$_2$. https://doi.org/10.1103/physrevb.101.205126

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