Valley hall transport of photon-dressed quasiparticles in two-dimensional Dirac semiconductors

TY - JOUR

T1 - Valley hall transport of photon-dressed quasiparticles in two-dimensional Dirac semiconductors

AU - Kovalev, V. M.

AU - Tse, Wang Kong

AU - Fistul, M. V.

AU - Savenko, I. G.

N1 - Publisher Copyright: © 2018 The Author(s). Published by IOP Publishing Ltd on behalf of Deutsche Physikalische Gesellschaft.

PY - 2018/8

Y1 - 2018/8

N2 - We present a theory of the photovoltaic valley-dependent Hall effect in a two-dimensional (2D) Dirac semiconductor subject to an intense near-resonant electromagnetic field. Our theory captures and elucidates the influence of both the field-induced resonant interband transitions and the nonequilibrium carrier kinetics on the resulting valley Hall transport in terms of photon-dressed quasiparticles (PDQs). The non-perturbative renormalization effect of the pump field manifests itself in the dynamics of the PDQs, with a quasienergy spectrum characterized by dynamical gaps δ η(η is the valley index) that strongly depend on field amplitude and polarization. Nonequilibrium carrier distribution functions are determined by the pump field frequency ω as well as the ratio of intraband relaxation time τ and interband recombination time τ recWe obtain analytic results in three regimes, when (I) all relaxation processes are negligible, (II) τ ≪ τrecand (III) τ ≫ τ recand display corresponding asymptotic dependences on δηand ω. We then apply our theory to 2D transition-metal dichalcogenides, and find a strong enhancement of valley-dependent Hall conductivity as the pump field frequency approaches the transition energies between the pair of spin-resolved conduction and valence bands at the two valleys.

AB - We present a theory of the photovoltaic valley-dependent Hall effect in a two-dimensional (2D) Dirac semiconductor subject to an intense near-resonant electromagnetic field. Our theory captures and elucidates the influence of both the field-induced resonant interband transitions and the nonequilibrium carrier kinetics on the resulting valley Hall transport in terms of photon-dressed quasiparticles (PDQs). The non-perturbative renormalization effect of the pump field manifests itself in the dynamics of the PDQs, with a quasienergy spectrum characterized by dynamical gaps δ η(η is the valley index) that strongly depend on field amplitude and polarization. Nonequilibrium carrier distribution functions are determined by the pump field frequency ω as well as the ratio of intraband relaxation time τ and interband recombination time τ recWe obtain analytic results in three regimes, when (I) all relaxation processes are negligible, (II) τ ≪ τrecand (III) τ ≫ τ recand display corresponding asymptotic dependences on δηand ω. We then apply our theory to 2D transition-metal dichalcogenides, and find a strong enhancement of valley-dependent Hall conductivity as the pump field frequency approaches the transition energies between the pair of spin-resolved conduction and valence bands at the two valleys.

KW - Photon-dressed quasiparticles

KW - Transition-metal dichalcogenides

KW - Two-dimensional materials

KW - Valley hall effect

UR - http://www.scopus.com/inward/record.url?scp=85053116340&partnerID=8YFLogxK

U2 - 10.1088/1367-2630/aad5f8

DO - 10.1088/1367-2630/aad5f8

M3 - 文章

AN - SCOPUS:85053116340

SN - 1367-2630

VL - 20

JO - New Journal of Physics

JF - New Journal of Physics

IS - 8

M1 - 083007

ER -