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Theoretical investigations on Kerr and Faraday rotations in topological multi-Weyl Semimetals
by Supriyo Ghosh, Ambaresh Sahoo, Snehasish Nandy
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Submission summary
| Authors (as registered SciPost users): | Snehasish Nandy |
| Submission information | |
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| Preprint Link: | https://arxiv.org/abs/2209.11217v5 (pdf) |
| Date accepted: | 2023-08-17 |
| Date submitted: | 2023-07-21 03:42 |
| Submitted by: | Nandy, Snehasish |
| Submitted to: | SciPost Physics |
| Ontological classification | |
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| Academic field: | Physics |
| Specialties: |
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| Approach: | Theoretical |
Abstract
Motivated by the recent proposal of giant Kerr rotation in WSMs, we investigate the Kerr and Faraday rotations in time-reversal broken multi-Weyl semimetals (mWSMs) in the absence of an external magnetic field. Using the framework of Kubo response theory, we find that both the longitudinal and transverse components of the optical conductivity in mWSMs are modified by the topological charge ($n$). Engendered by the optical Hall conductivity, we show in the thin film limit that, while the giant Kerr rotation and corresponding ellipticity are independent of $n$, the Faraday rotation and its ellipticity angle scale as $n$ and $n^2$, respectively. In contrast, the polarization rotation in semi-infinite mWSMs is dominated by the axion field showing $n$ dependence. In particular, the magnitude of Kerr (Faraday) angle decreases (increases) with increasing $n$ in Faraday geometry, whereas in Voigt geometry, it depicts different $n$-dependencies in different frequency regimes. The obtained results on the behavior of polarization rotations in mWSMs could be used in experiments as a probe to distinguish single, double, and triple WSMs, as well as discriminate the surfaces of mWSMs with and without hosting Fermi arcs.
Author comments upon resubmission
List of changes
Summary of changes in response to referee report
1) In response to referee comment 1, we have added a relevant comment on qualitative differences between a conventional WSM and mWSM in the revised manuscript. (First and second paragraph of the discussion and conclusion section, Right column, Page 10)
2) In response to referee comment 2, we have added a relevant comment on trivial band contribution to polarization rotation in the third paragraph of the discussion and conclusion section of the revised manuscript. (Left column, Page 11)
Published as SciPost Phys. 15, 133 (2023)