Surface photogalvanic effect in Weyl semimetals

Abstract

The photogalvanic effect -- a rectified current induced by light irradiation -- requires the intrinsic symmetry of the medium to be sufficiently low, which strongly limits candidate materials for this effect. In this work we explore how in Weyl semimetals the photogalvanic effect can be enabled and controlled by design of the material surface. Specifically, we provide a theory of ballistic linear and circular photogalvanic current in a Weyl semimetal spatially confined to a slab under general and variable surface boundary conditions. The results are applicable to Weyl semimetals with an arbitrary number of Weyl nodes at radiation frequencies small compared to the energy of non-linear terms in the dispersion at the Fermi level. The confinement-induced response is tightly linked to the configuration of Fermi-arc surface states, specifically the Fermi-arc connectivity and direction of emanation from the Weyl nodes, thus inheriting the same directionality and sensitivity to boundary conditions. As a result, the photogalvanic response of the system becomes much richer than that of an infinite system, and may be tuned via surface manipulations.

13 pages + 12 pages appendix, 8 Figures

References in corpus (8)

• Anomalous Hall Effect in Weyl Metals
• Photocurrents in Weyl semimetals
• Semiclassical theory of nonlinear magneto-optical responses with applications to topological Dirac/Weyl semimetals
• Robust edge photocurrent response on layered Type II Weyl semimetal WTe2
• Photogalvanic effect in Weyl semimetals
• Shift charge and spin photocurrents in Dirac surface states of topological insulator
• Towards Weyltronics: Realization of epitaxial NbP and TaP Weyl Semimetal thin films
• Photocurrents in gyrotropic Weyl semimetals

Cited by in corpus (7)

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• Revealing Quantum Geometry in Nonlinear Quantum Materials
• Linear photogalvanic effect in surface states of topological insulators
• Photocurrents induced by structured light
• Helicity-dependent Ultrafast Photocurrents in Weyl Magnet Mn${}_3$Sn
• Manipulating Photogalvanic Effects in Two-Dimensional Multiferroic Breathing Kagome Materials
• Nonlinear response functions and disorder: the case of photogalvanic effect