Plasmon spectrum of two-dimensional electron systems with Rashba spin-orbit interaction

X. F. Wang

Phys. Rev. B 72, 085317 – Published 4 August 2005; Erratum Phys. Rev. B 75, 079902 (2007)

Abstract

The dielectric function and plasmon modes of a two-dimensional electron gas (2DEG) are studied in single- and double-quantum-well structures with Rashba spin-orbit interaction (RSOI) in the framework of the random-phase approximation. The RSOI splits each parabolic energy subband of a 2DEG into two nonparabolic spin branches and affects the electronic many-body correlation and dielectric properties of the 2DEG. The influence of the RSOI on the 2DEG plasmon spectrum in single quantum wells appears mainly in three ways: (1) an overall frequency lowering due to the energy band deformation; (2) a weak frequency oscillation stemming from the spin-split energy band; and (3) an enhancement of the Landau damping as a result of the emerging of the interbranch single-particle-excitation spectrum. In double quantum wells, the above effects are enhanced for the optic plasmon mode but diminished for the acoustic one.