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arXiv · 2208.08586

Unconventional optical selection rules in ZrTe5 under an in-plane magnetic field

Yi-Xiang Wang·Fuxiang Li
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Abstract

The optical selection rules of an electron system under a magnetic field play key roles in determining its optical properties, from which the band structures and underlying symmetries can be derived. In this Letter, based on a three-dimensional strong topological insulator model describing ZrTe5,we study the Landau levels (LLs) and magneto-optical conductivity under an in-plane magnetic field. We reveal that in the transverse conductivity Re(σ_{zz}), the unconventional optical selection rules n\righatarrow n\pm 2 dominate, with n being the LL index. We attribute the unconventional selection rules to the peculiar distribution of parity carried by the LLs, resulting from the chiral symmetry of the sub-Hamiltonians. Moreover, we predict that, if the strong anisotropic system is tuned to be nearly isotropic, the LLs would redistribute and the conventional selection rules n\rightarrow n\pm 1 can be recovered.

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Yi-Xiang Wang, Fuxiang Li. 2022-11-02. Unconventional optical selection rules in ZrTe5 under an in-plane magnetic field. https://doi.org/10.1103/physrevb.106.205102

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