Low-temperature linear transport of two-dimensional massive Dirac fermions in silicene: residual conductivity and spin/valley Hall effects

TL;DR

This paper investigates the transport properties of two-dimensional massive Dirac fermions in silicene at finite temperature, revealing residual conductivity within the energy gap and impurity effects on spin and valley Hall conductivities.

Contribution

It introduces a kinetic equation approach to analyze how impurity scattering influences conductivity and Hall effects in silicene's massive Dirac fermions.

Findings

Residual conductivity exists within the energy gap due to interband correlation.

Impurity interactions significantly affect spin- and valley-Hall conductivities.

Conductivities depend on chemical potential, temperature, and gap energy.

Abstract

Considering finite-temperature screened electron-impurity scattering, we present a kinetic equation approach to investigate transport properties of two-dimensional massive fermions in silicene. We find that the longitudinal conductivity is always nonvanishing when chemical potential lies within the energy gap. This residual conductivity arises from interband correlation and strongly depends on strength of electron-impurity scattering. We also clarify that the electron-impurity interaction makes substantial contributions to the spin- and valley-Hall conductivities, which, however, are almost independent of impurity density. The dependencies of longitudinal conductivity as well as of spin- and valley-Hall conductivities on chemical potential, on temperature, and on gap energy are analyzed.