Speaker
Dr
David Lacoste
(ESPCI)
Description
Stochastic thermodynamics is a framework for extending
notions of classical thermodynamics to the level of
individual trajectories which can be recorded in
non-equilibrium conditions. While this framework is well
established for stochastic systems described by markovian
processes, the situation is less well understood when the
strength of the noise depends on the driving or when
non-markovian dynamics is involved. Such situations are not
purely academic but arise in soft matter or biological systems.
In the first part of the talk, I will present an
experimental study of a model system made of magnetic
colloidal particles which are manipulated using a
time-dependent magnetic field. By recording the
trajectories of the colloidal particles, the distributions
of thermodynamic quantities such as work or heat can be
obtained. This experiment is interesting because (i) it
involves state dependent hydrodynamic friction and (ii) it
can be carried out with more than one degree of freedom.
In the second part of this talk, I will review a set of
formal results which we obtained recently by generalizing
the Hatano-Sasa relation to systems which have been prepared
initially in a non-stationary non-equilibrium state. Such
results include a generalized fluctuation-dissipation
theorem and second-law like inequalities for non-equilibrium
systems.
