Active Matter Transport and Jamming on Disordered Landscapes
  We numerically examine the transport of active run-and-tumble particles driven with a drift force over random disordered landscapes comprised of fixed obstacles. For increasing run lengths, the net particle transport initially increases before reaching a maximum and decreasing at larger run lengths. The transport reduction is associated with the formation of cluster or living crystal states that become locally jammed or clogged by the obstacles. We also find that the system dynamically jams at lower particle densities when the run length is increased. Our results indicate that there is an optimal activity level for active matter transport through quenched disorder, and could be important for understanding biological transport in complex environments or for applications of active matter particles in random media. 
C. Reichhardt and C.J. Olson Reichhardt
cond-mat.soft cond-mat.stat-mech