Aging regime in a fragile glass former: study of a Brownian motor

No work can be extracted from an isolated system in equilibrium with a
single thermostat. Nevertheless there are systems, e.g. glass-forming
liquids, where relaxation to the thermostat temperature is so slow
that two different temperatures can be defined within the same system:
the temperature of the thermostat and the effective temperature
associated to the violation of the equilibrium fluctuation-dissipation
ratio. Here we present the first numerical study which shows how is
possible, by introducing a proper brownian motor, to extract work from
the out-of-equilibrium regime of a glass-forming liquid.