Helicity-dependent photocurrents in the chiral Weyl semimetal RhSi

Rees D, Manna K, Lu B, Morimoto T, Borrmann H, Felser C, Moore JE, Torchinsky DH, Orenstein J (2020)

Publication Type: Journal article

Publication year: 2020

Journal

Science Advances American Association for the Advancement of Science

Book Volume: 6

Article Number: eaba0509

Journal Issue: 29

DOI: 10.1126/sciadv.aba0509

Abstract

Weyl semimetals are crystals in which electron bands cross at isolated points in momentum space. Associated with each crossing point (or Weyl node) is a topological invariant known as the Berry monopole charge. The circular photogalvanic effect (CPGE), whereby circular polarized light generates a helicity-dependent photocurrent, is a notable example of a macroscopic property that emerges directly from the topology of the Weyl semimetal band structure. Recently, it was predicted that the amplitude of the CPGE associated with optical transitions near a Weyl node is proportional to its monopole charge. In chiral Weyl systems, nodes of opposite charge are nondegenerate, opening a window of wavelengths where the CPGE resulting from uncompensated Berry charge can emerge. Here, we report measurements of CPGE in the chiral Weyl semimetal RhSi, revealing a CPGE response in an energy window that closes at 0.65 eV, in agreement with the predictions of density functional theory.

Involved external institutions

University of California, Berkeley US United States (USA) (US) Max-Planck-Institut für Chemische Physik fester Stoffe (MPI CPfS) / Max Planck Institute for Chemical Physics of Solids DE Germany (DE) Temple University US United States (USA) (US)

How to cite

APA:

Rees, D., Manna, K., Lu, B., Morimoto, T., Borrmann, H., Felser, C.,... Orenstein, J. (2020). Helicity-dependent photocurrents in the chiral Weyl semimetal RhSi. Science Advances, 6(29). https://doi.org/10.1126/sciadv.aba0509

MLA:

Rees, Dylan, et al. "Helicity-dependent photocurrents in the chiral Weyl semimetal RhSi." Science Advances 6.29 (2020).

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