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arXiv · 2009.00873

Signature of band inversion in the antiferromagnetic phase of axion insulator candidate EuIn2As2

Takafumi Sato·Zhiwei Wang·Daichi Takane·Seigo Souma·Chaoxi Cui·Yongkai Li·Kosuke Nakayama·Tappei Kawakami·Yuya Kubota·Cephise Cacho·Timur K. Kim·Arian Arab·Vladimir N. Strocov·Yugui Yao·Takashi Takahashi
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Abstract

We have performed angle-resolved photoemission spectroscopy on EuIn2As2 which is predicted to be an axion insulator in the antiferromagnetic state. By utilizing soft-x-ray and vacuum-ultraviolet photons, we revealed a three-dimensional hole pocket centered at the Gamma point of bulk Brillouin zone together with a heavily hole-doped surface state in the paramagnetic phase. Upon entering the antiferromagnetic phase, the band structure exhibits a marked reconstruction characterized by the emergence of a "M"-shaped bulk band near the Fermi level. The qualitative agreement with first-principles band-structure calculations suggests the occurrence of bulk-band inversion at the Gamma point in the antiferromagnetic phase. We suggest that EuIn2As2 provides a good opportunity to study the exotic quantum phases associated with possible axion-insulator phase.

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Takafumi Sato, Zhiwei Wang, Daichi Takane, Seigo Souma, Chaoxi Cui, Yongkai Li, Kosuke Nakayama, Tappei Kawakami, Yuya Kubota, Cephise Cacho, Timur K. Kim, Arian Arab, Vladimir N. Strocov, Yugui Yao, Takashi Takahashi. 2020-09-02. Signature of band inversion in the antiferromagnetic phase of axion insulator candidate EuIn2As2. https://doi.org/10.1103/physrevresearch.2.033342

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