Thomas-Fermi-Dirac-von Weizsacker hydrodynamics in laterally modulated electronic systems

摘要

We have studied the collective plasma excitations of a two-dimensionalelectron gas with an arbitrary lateral charge-density modulation. The dynamicsis formulated using a previously developed hydrodynamic theory based on theThomas-Fermi-Dirac-von Weizsacker approximation. In this approach, both theequilibrium and dynamical properties of the periodically modulated electron gasare treated in a consistent fashion. We pay particular attention to theevolution of the collective excitations as the system undergoes the transitionfrom the ideal two-dimensional limit to the highly-localized one-dimensionallimit. We also calculate the power absorption in the long-wavelength limit toillustrate the effect of the modulation on the modes probed by far-infrared(FIR) transmission spectroscopy.