On the oscillatory behaviour of velocity autocorrelation function of a 2D electron liquid

The velocity autocorrelation function (VAF) and the dynamic structure factor of a two-dimensional electron liquid are studied using molecular dynamics techniques. The VAF exhibits well defined oscillations whose frequency is independent of the dimensionless coupling parameter Gamma . The oscillations arise from a coupling between the single-particle motion and the longitudinal collective modes whose wavevector is nearly equal to the inverse interparticle separation.