Effective temperature in driven vortex lattices with random pinning
  We study numerically correlation and response functions in non-equilibrium driven vortex lattices with random pinning. From a generalized fluctuation-dissipation relation we calculate an effective transverse temperature in the fluid moving phase. We find that the effective temperature decreases with increasing driving force and becomes equal to the equilibrium melting temperature when the dynamic transverse freezing occurs. We also discuss how the effective temperature can be measured experimentally from a generalized Kubo formula. 
Alejandro B. Kolton, Raphael Exartier, Leticia Cugliandolo, Daniel   Dominguez and Niels Gronbech-Jensen