Edge Waves in Odd Fluids

In a fluid of chiral particles, the explicit breaking of parity symmetry allows for the existence of a non-dissipative viscosity coefficient, known as the odd (a.k.a. Hall) viscosity. In many cases, the bulk fluid flow remains unaffected by this coefficient. However, the existence of odd viscosity has striking consequences on boundary flows. In this talk, I will discuss the phenomenology of edge waves in 2+1d non-relativistic fluids with odd (aka Hall) viscosity. In particular, we study free surface waves under the condition of vanishing stress. We find that the propagating edge waves at wave vector k are characterized by a universal dispersion 2 η k│k│ proportional to the odd viscosity . Furthermore, we find that the fluid flow exhibits a boundary layer which leads to singular flow solutions in the incompressible inviscid limit. Finally, we connect this phenomenology to electronic fluids in a magnetic field, in particular the quantum Hall effect, and discuss experimental signatures of the odd flow.