How to generate and measure anomalous weakly non-ergodic Brownian motion in simple systems

Abstract

It is shown that in systems with time-dependent and/or spatially nonuniform temperature $T(t,x)$, (i) most of the transport processes is weakly non-ergodic, and (ii) the diffusion (Brownian motion, BM) is anomalous. A few examples of simple arrangements, easy for experimental realization, are discussed in detail. Proposed measurements will enable also the observation of transitions from ergodic to weakly non-ergodic and from normal to anomalous diffusion. New effects are predicted: (i) zero-mean oscillations of $T(t)$ accelerate BM (pumping effect), (ii) the combination of temporal and spatial variations of temperature may lead to superballistic BM, (iii) linear gradients of $T(x)$ result in an exponential acceleration of BM. One can expect similar effects in inflationary systems with time-dependent metrics.