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Résumé |
There is intense experimental interest in transport in ultraclean (often 2D) materials
where electron-electron interactions dominate over phonon and impurity scattering. In this
regime, electron flow is described by a hydrodynamic framework, with transport coefficients
such as the shear viscosity derived from Fermi-liquid theory. While one could think that this
framework should be fully understood, it turns out that there are still fundamental aspects
of Fermi-liquid theory that remain unexplored. In this talk, I will review hydrodynamic
transport in 2D Fermi liquids and show that Pauli blocking gives rise to excitations whose
lifetimes are parametrically longer than conventionally expected. This effect is not restricted
to charged electron liquids but is also expected to occur for neutral quantum gases. I will
conclude by discussing how these long-lived modes modify the standard hydrodynamic description of electron flow in mesoscopic devices, and in particular lead to extended boundary
layers and a strong sensitivity to magnetic fields. |
