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Quantized circular photogalvanic effect in Weyl semimetals.

ABSTRACT: The circular photogalvanic effect (CPGE) is the part of a photocurrent that switches depending on the sense of circular polarization of the incident light. It has been consistently observed in systems without inversion symmetry and depends on non-universal material details. Here we find that in a class of Weyl semimetals (for example, SrSi₂) and three-dimensional Rashba materials (for example, doped Te) without inversion and mirror symmetries, the injection contribution to the CPGE trace is effectively quantized in terms of the fundamental constants e, h, c and with no material-dependent parameters. This is so because the CPGE directly measures the topological charge of Weyl points, and non-quantized corrections from disorder and additional bands can be small over a significant range of incident frequencies. Moreover, the magnitude of the CPGE induced by a Weyl node is relatively large, which enables the direct detection of the monopole charge with current techniques.

SUBMITTER: de Juan F

PROVIDER: S-EPMC5504287 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature

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Quantized circular photogalvanic effect in Weyl semimetals.

de Juan Fernando F Grushin Adolfo G AG Morimoto Takahiro T Moore Joel E JE

Nature communications 20170706

The circular photogalvanic effect (CPGE) is the part of a photocurrent that switches depending on the sense of circular polarization of the incident light. It has been consistently observed in systems without inversion symmetry and depends on non-universal material details. Here we find that in a class of Weyl semimetals (for example, SrSi<sub>2</sub>) and three-dimensional Rashba materials (for example, doped Te) without inversion and mirror symmetries, the injection contribution to the CPGE tr ...[more]

PMID: 28681840

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