You don't need complicated setups with superconductors. To a surprisingly good approximation the conduction electrons in a metal behave as a nearly ideal gas. This is the free electron gas model, or unexcitingly named nearly free electron gas model.

This electron gas supports oscillations that are the equivalent of sound waves, and with these comes a quasiparticle analogous to the phonon called the plasmon.

When I was doing my PhD there was lots of interest in plasmons. I'm not sure how active an area it is these days - I get the impression that the more esoteric aspects of electronic structure have largely taken over - but a quick Google will find lots of related material.