Electronic sound modes and plasmons in hydrodynamic two-dimensional metals
Andrew Lucas, S. Das Sarma
Using an analytically tractable kinetic model of a two-dimensional Fermi liquid of electrons, we characterize the crossovers among zero sound, first sound, and plasmons. For experimentally realized Fermi liquids in a hydrodynamic limit, both zero and first sound waves are essentially replaced by plasmons. The plasmon dispersion relation is robust against hydrodynamic effects up to acquiring the viscous-limited decay rate of a first sound wave in the hydrodynamic limit. We discuss implications for experiments in clean two-dimensional electron gases.
arXiv:1801.01495•Physical review. B./Physical review. B•Mar 28, 2018•66 citations