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arXiv · 2403.10898

Role of Coulomb interaction in the valley photogalvanic effect

V. M. Kovalev·A. V. Parafilo·O. V. Kibis·I. G. Savenko
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Abstract

We develop a theory of Coulomb interaction-related contribution to the photogalvanic current of the carriers of charge in two-dimensional non-centrosymmetric Dirac materials possessing a nontrivial structure of valleys and exposed to an external electromagnetic field. The valley photogalvanic effect occurs here due to the trigonal warping of electrons and holes' dispersions in a given valley of the monolayer. We study the low-frequency limit of the external field: The field frequency is smaller than the temperature $T$, and the electron-electron and electron-hole scattering times are much larger than the electron-impurity and hole-impurity scattering times. In this regime, we employ the Boltzmann transport equations and show that electron-hole scattering dominates electron-electron scattering in intrinsic semiconductors. A Coulomb electron-hole interaction-related contribution to the valley photogalvanic current can reduce the value of the bare photogalvanic current as electron and hole currents flow in opposite directions.

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V. M. Kovalev, A. V. Parafilo, O. V. Kibis, I. G. Savenko. 2024-03-16. Role of Coulomb interaction in the valley photogalvanic effect. https://doi.org/10.1103/physrevb.109.245414

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