The Ratchet effect in an ageing glass

TL;DR

This paper investigates the ratchet effect in an ageing glass, revealing how an asymmetric intruder exhibits a steady drift after a quench, with dynamics linked to an effective temperature and modeled by a Sinai-like system.

Contribution

It demonstrates the emergence of a ratchet effect in an ageing glass and connects it to an effective temperature concept, supported by a Sinai model analogy.

Findings

Net drift appears after a quench below the mode-coupling temperature.

The subvelocity scales with the ratio of effective temperature to bath temperature.

The phenomenon is explained by a thermal ratchet mechanism involving two reservoirs.

Abstract

We study the dynamics of an asymmetric intruder in a glass-former model. At equilibrium, the intruder diffuses with average zero velocity. After an abrupt quench to $T$ deeply under the mode-coupling temperature, a net average drift is observed, steady on a logarithmic time-scale. The phenomenon is well reproduced in an asymmetric version of the Sinai model. The subvelocity of the intruder grows with $T_{eff}/T$, where $T_{eff}$ is defined by the response-correlation ratio, corresponding to a general behavior of thermal ratchets when in contact with two thermal reservoirs.