Dielectric response function and plasmon dispersion in a strongly coupled two-dimensional Coulomb liquid

We have formulated a dielectric response function for strongly coupled two-dimensional Coulomb liquids in the T=0 quantum domain. The formulation is based on the classical quasilocalized charge approximation [G. Kalman and K.I. Golden, Phys. Rev. A 41, 5516 (1990); K.I. Golden and G. Kalman, Phys. Plasmas 7, 14 (2000)] and extends the QLCA formalism into the quantum domain. We calculate the dispersion of the longitudinal plasmon mode for r(s) =10, 20, 40 and the resulting dispersion curves are compared with recent experimental results. We also conjecture the possible existence of a new high-wave-number collective excitation in close proximity to the right boundary of the pair continuum.