Memory effects in the electron glass

Abstract

We investigate theoretically the slow nonexponential relaxation dynamics and associated memory effects of glasses far from equilibrium, which are arguably the most important characteristics of the glass phase. We focus on the electron glass which offers an advantageous starting point compared to other glassy systems both theoretically and experimentally: the model used here is discrete, and experimentally it offers new ways to address these effects by changing a simple experimental parameter —the gate voltage. The full nonlinearized self-consistent model of the dynamics of the occupation numbers in the system successfully recovers the general behavior found in experiments. Our numerical analysis is consistent with both the expected logarithmic relaxation and our understanding of how increasing disorder or interaction slows down the relaxation process, thus yielding a consistent picture of the electron glass, and shedding light on the understanding of glassy behavior in general. We also present a novel finite-size domino effect where the connection to the leads affects the relaxation process of the electron glass in mesoscopic systems. This effect speeds up the relaxation process, and may even reverse the expected effect of interaction; stronger interaction then leading to a faster relaxation.