Disorder-Induced Anomalous Mobility Enhancement in Confined Geometries

Abstract

Strong, scale-free disorder disrupts typical transport properties like the Stokes-Einstein relation and linear response, leading to anomalous, non-diffusive motion observed in amorphous materials, glasses, living cells, and other systems. Our study reveals that the combination of scale-free quenched disorder and geometrical constraints induces unconventional single particle mobility behavior. Specifically, in a $2$-dimensional channel with width $w$, under external drive, tighter geometrical constraints (smaller $w$) enhance mobility. We derive an explicit form of the response to an external force by utilizing the double-subordination approach for the quenched trap model. The observed mobility enhancement occurs in the low-temperature regime where the distribution of localization times is scale-free.