Diffusive regimes in a two-dimensional chiral fluid

We study the experimental behavior of diffusion in a chiral flow (produced in this case by a set of identical disk-shaped rotors). Results display in general — but not always— strong anisotropic diffusion, represented here by an antisymmetric two-dimensional tensor. In particular, we show chiral diffusion is, strikingly, very slowly aging. Moreover, we show that the same chiral fluid may feature either strong super-diffusive behavior, quasi-normal diffusion, or weak sub-diffusion, depending on the flow chiral vorticity value. Moreover, off-diagonal diffusion coefficients (odd diffusion coefficient) change sign according to this scheme as well. Therefore, the chiral fluid appears to have a strikingly complex and self regulated diffusive behavior.