Shin-ichi Sasa

THERMODYNAMICS, FLUCTUATIONS, AND RESPONSE, FOR SYSTEMS DRIVEN OUT OF EQUILIBRIUM

Thermodynamics is a framework that formalizes a fundamental limitation of possible operations to equilibrium systems and also that provides a unified description of properties of materials under equilibrium conditions. These two aspects can be described by a single thermodynamic function. Furthermore, the large deviation function of  macroscopic fluctuations can be expressed in terms of a thermodynamic function, and as the result, response properties are related to fluctuations.
 
However, all the relations mentioned above are not applied to systems driven out of equilibrium. Then,  as the first step of studying non-equilibrium statistical mechanics, it is an important problem to seek for universal relations associated with thermodynamics, fluctuations and response for such systems.
 
In my talk, I will present our recent resultsfor this problem with emphasizing the inter-relation among them. The representative references are the following:
 
 (1) T. Hatano and S. Sasa,
 Steady state thermodynamics of Langevin systems,
 Phys. Rev. Lett. 86, 3463-3466 (2001).
 
 (2) S. Sasa and H. Tasaki, Steady state thermodynamics,
 J. Stat. Phys. 125, 125-227, (2006).