2020/06/30 by Tomer Markovich, Tom C. Lubensky
Physics and Astronomy · #cond-mat.soft #cond-mat.stat-mech #physics.flu-dyn
paper · pdf · doi:10.1103/physrevlett.127.048001
published as Phys. Rev. Lett. 127, 048001 (2021) · 17 pages, 6 figures
arxiv created 2021/05/13 · arxiv updated 2021/07/28
In common fluids, viscosity is associated with dissipation. However, when time-reversal-symmetry is broken a new type of non-dissipative `viscosity' may emerge. Recent theories and experiments on classical 2D systems with active spinning particles have heightened interest in odd viscosity, but a microscopic theory for it in active materials is still absent. Here we present such first-principles microscopic Hamiltonian theory, valid for both 2D and 3D, showing that odd viscosity is present in any system, equilibrium or not, with aligned spinning components. Our work substantially extends the applicability of odd viscosity into 3D fluids, and specifically to internally driven active materials, such as living matter (e.g., actomyosin gels). We find intriguing 3D effects of odd viscosity such as propagation of anisotropic bulk shear waves and breakdown of Bernoulli's principle.