Residual bulk viscosity of a disordered two-dimensional electron gas
Nonzero bulk viscosity signals breaking of the scale invariance. We demonstrate that disorder in a two-dimensional noninteracting electron gas in a perpendicular magnetic field results in nonzero disorder-averaged bulk viscosity. We derive an analytic expression for the bulk viscosity within the self-consistent Born approximation. This residual bulk viscosity provides the lower bound for the bulk viscosity of 2D interacting electrons at low enough temperatures.