Odd viscosity-induced Hall-like transport of an active chiral fluid

Proc Natl Acad Sci U S A. 2022 Oct 18;119(42):e2201279119. doi: 10.1073/pnas.2201279119. Epub 2022 Oct 10.

Abstract

Broken time-reversal and parity symmetries in active spinner fluids imply a nondissipative "odd viscosity," engendering phenomena unattainable in traditional passive or active fluids. Here we show that the odd viscosity itself can lead to a Hall-like transport when the active chiral fluid flows through a quenched matrix of obstacles, reminiscent of the anomalous Hall effect. The Hall-like velocity depends significantly on the spinner activity and longitudinal flow due to the interplay between odd viscosity and spinner-obstacle collisions. Our findings underscore the importance of odd viscosity in active chiral matter and elucidate its essential role in the anomalous Hall-like effect.

Keywords: Hall-like flow; active chiral matter; collective behavior; odd viscosity.