Disorder


 Active particles moving on a disordered landscape:

yellow ball On coarse scales, the random landscape can be regarded as a collection of randomly placed pumps (fixed inclusions)

Density response of non-interacting active particles on such a landscape can be obtained by superposition:

The superposition generates a highly (power-law) correlated state, such that

   

Disorder also leads to persistent currents in this state (since the random force field is not curl-free)

OK,

Sunghan Ro, Y. Kafri, M. Kardar, J. Tailleur, Phys. Rev. Lett. 126, 048003 (2021)