Photogalvanic currents in dynamically gapped Dirac materials

Abstract

We develop a microscopic theory of an unconventional photogalvanic effect in two-dimensional materials with the Dirac energy spectrum of the carriers of charge under strong driving. As a test bed, we consider a layer of a transition metal dichalcogenide, exposed to two different electromagnetic fields. The first pumping field is circularly-polarized, and its frequency exceeds the material bandgap. It creates an extremely nonequilibrium distribution of electrons and holes in one valley (K) and opens dynamical gaps, whereas the other valley (K') remains empty due to the valley-dependent interband selection rules. The second probe field has the frequency much smaller than the material bandgap. It generates intraband perturbations of the nonequilibrium carriers density, resulting in the photogalvanic current due to the trigonal asymmetry of the dispersions. This current shows threshold-like behavior due to the dynamical gap opening and renormalizations of the density of states and velocity of quasiparticles.

Manuscript: 6 pages, 2 figures

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Cited by in corpus (8)

• Valley Acoustoelectric Effect
• Photogalvanic transport in fluctuating Ising superconductors
• Nonlinear circular valley photogalvanic effect
• Acoustomagnetoelectric effect in two-dimensional materials: Geometric resonances and Weiss oscillations
• Coherent photogalvanic effect in fluctuating superconductors
• Role of Coulomb interaction in the valley photogalvanic effect
• Renormalization of the valley Hall conductivity due to interparticle interaction
• Largely enhanced photogalvanic effects in the phosphorene photodetector by strain-increased device asymmetry