Dynamical structure factor of a quantum wire in the random-phase approximation

We present self-consistent calculations of the single-particle and collective excitations in a quasi-one-dimensional electron gas or quantum wire. The dynamical structure factor, evaluated in the random-phase approximation (RPA), displays unique line shapes and dispersion relations which are in sharp contrast with the results expected for higher-dimensional electron gases. A well-defined spectral feature is attributed to an acoustic plasmon. The calculated shift of the intersubband resonance frequency, caused by the depolarization effect, agrees well with previous experiments.