Collective Excitations of a Two-Component One-Dimensional Quantum Plasma Confinedin Semiconductor Quantum Wires

摘要

The collective plasmon excitation spectrum of a one dimensional electron gasconfined in a GaAs quantum wire is calculated within the two subband random phase approximation. We calculate the collective charge density excitation (CDE) dispersion assuming that both the ground and the first excited subband states are occupied by electrons. We find four different branches of CDE modes, two of which are intrasubband ODE's and the other two intersubband ODE's. The mode coupling effect between them is investigated by introducing a parity breaking asymmetry in the confinement potential. Our calculated mode dispersion is in excellent quantitative agreement with a recent inelastic light scattering experiment.