Inelastic lifetimes of confined two-component electron systems in semiconductor quantum wire and quantum well structures

TL;DR

This paper calculates electron scattering lifetimes in two-component quantum wires and double-layer quantum wells, revealing the roles of particle-hole and plasmon excitations and their impact on inelastic lifetimes.

Contribution

It provides a detailed analysis of Coulomb scattering lifetimes in two-component electron systems, highlighting differences from single-subband systems and clarifying plasmon contributions.

Findings

Scattering rate in two-subband quantum wires includes particle-hole and plasmon effects.

Acoustic plasmon contribution does not alter low-energy lifetime significantly.

No linear energy dependence of scattering rate as seen in high-$T_c$ superconductors.

Abstract

We calculate Coulomb scattering lifetimes of electrons in two-subband quantum wires and in double-layer quantum wells by obtaining the quasiparticle self-energy within the framework of the random-phase approximation for the dynamical dielectric function. We show that, in contrast to a single-subband quantum wire, the scattering rate in a two-subband quantum wire contains contributions from both particle-hole excitations and plasmon excitations. For double-layer quantum well structures, we examine individual contributions to the scattering rate from quasiparticle as well as acoustic and optical plasmon excitations at different electron densities and layer separations. We find that the acoustic plasmon contribution in the two-component electron system does not introduce any qualitatively new correction to the low energy inelastic lifetime, and, in particular, does not produce the linear energy dependence of carrier scattering rate as observed in the normal state of high-$T_c$ superconductors.