Correlation effects on plasmon dispersion of a dilute two-dimensional electron gas at finite temperature

Abstract

We have studied theoretically the effect of correlations on the plasmon dispersion of a dilute two-dimensional electron gas, realized in a narrow GaAs quantum well and probed recently using inelastic light scattering experiments by Hirjibehedin et al. The plasmon energy is obtained from the poles of the electron density response function determined by employing the finite temperature version of the self-consistent mean-field theory of Singwi et al. Our results show an excellent agreement with the experimental data, but it is vital to incorporate the exchange-correlation effects and their dependence on the temperature. Interestingly, plasmon energy shows a blue shift with increasing temperature, and the correlation effects which grow with decreasing electron density, introduce a red shift. These findings may be of practical importance in the design of plasmonic devices.