Linear-in-temperature conductance in two-dimensional electron fluids

A hallmark of electron hydrodynamics---a transport regime dominated by electron collisions---is that collisions enhance conduction and reduce dissipation, causing resistance to drop and conductance to rise with temperature ($T$). Here, the authors present a microscopic study of two-dimensional electron fluids, predicting linear-in-$T$ scaling of hydrodynamic conductance. This behavior, contrasting with the ${T}^{2}$ scaling in three-dimensional Fermi liquids, arises from a cascade of multiple long-lived viscous modes unique to two-dimensional systems. The number of modes relevant for transport grows as $T$ decreases, resulting in a non-Fermi-liquid linear-in-$T$ behavior.