Nonlinear Physics Seminar: "The long-ranged influence of disorder on active systems"

Wed, 27/10/202112:00-13:30
Danciger B Building, Seminar room
Lecturer: Yariv Kafri, Technion

The talk will describe the impact of quenched random potentials on active matter. By developing a methodology for studying these systems both bulk and boundary disorder will be considered. For dilute systems it will be shown that bulk disorder leads to generic long-range correlations, decaying as a power-law, and steady-state currents. Disorder localized along a wall confining the system leads to long-range density modulations and eddies whose amplitude decays as a power law with the distance from the wall, but whose extent grows with it. The talk will also consider dense scalar active systems whose sole hydrodynamic mode is the density. These are known to exhibit a motility induced phase separation in dimensions d \geq 2. It will be shown that bulk potential disorder destroys the transition in dimensions d<4, while boundary disorder destroys it in dimensions d<3.