Electron-electron scattering and transport properties of spin-orbit coupled electron gas

Abstract

We calculate the electrical and thermal conductivity of a two-dimensional electron gas with strong spin-orbit coupling in which the scattering is dominated by electron-electron collisions. Despite the apparent absence of Galilean invariance in the system, the two-particle scattering does not affect the electrical conductivity above the band-crossing point where both helicity bands are filled. Below the band-crossing point where one helicity band is empty, switching on the electron-electron scattering leads only to a limited decrease of the electrical conductivity, so that its high-temperature value is independent of the scattering intensity. In contrast to this, thermal conductivity is not strongly affected by the spin-orbit coupling and exhibits only a kink as the Fermi level passes through the band-crossing point.

Finite-frequency response of Rasba electron gas with two-particle scattering

“…with zero relaxation rate. This is the reason why the electron-electron scattering alone cannot ensure a finite dc conductivity even for multiband electron systems [10].…”

“…It is noteworthy that neither σ ee nor σ ee contains the ln −1 (E F /T ) factor, much like the dc conductivity in a presence of weak impurity scattering [10].…”

“…In this paper, we calculate the finite-frequency and finite-temperature electric response of two-dimensional (2D) Rashba electron gas with electron-electron scattering beyond the perturbation theory. To this end, we use the Boltzmann equation similar to that derived recently [10] for calculating the dc conductivity of these systems. Despite the lack of Galilean invariance, the Rashba electron gas is translationally invariant and therefore there is a perturbation of electron distribution of a definite form that is stable with respect to electron-electron collisions.…”