2018/02/28 by Anton Souslov, Kinjal Dasbiswas, Michel Fruchart +2
Physics and Astronomy · #cond-mat.soft
paper · pdf · doi:10.1103/physrevlett.122.128001
published as Phys. Rev. Lett. 122, 128001 (2019) · 16 pages including Supplementary Information, 11 figures. See https://www.youtube.com/watch?v=PYeb88vwoJ0 for Supplementary Movie
arxiv created 2019/05/27 · arxiv updated 2019/05/28
Fluids in which both time-reversal and parity are broken can display a dissipationless viscosity that is odd under each of these symmetries. Here, we show how this odd viscosity has a dramatic effect on topological sound waves in fluids, including the number and spatial profile of topological edge modes. Odd viscosity provides a short-distance cutoff that allows us to define a bulk topological invariant on a compact momentum space. As the sign of odd viscosity changes, a topological phase transition occurs without closing the bulk gap. Instead, at the transition point, the topological invariant becomes ill-defined because momentum space cannot be compactified. This mechanism is unique to continuum models and can describe fluids ranging from electronic to chiral active systems.