5 research outputs found
A simple system with two temperatures
We study the stationary nonequilibrium regime which settles in when two
single-spin paramagnets each in contact with its own thermal bath are coupled.
The response vs. correlation plot exhibits some features of aging systems, in
particular the existence, in some regimes, of effective temperatures.Comment: 7 pages, 3 figure
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.Comment: 4 pages, 4 figure
Slow relaxations and history dependence of the transport properties of layered superconductors
We study numerically the time evolution of the transport properties of
layered superconductors after different preparations. We show that, in
accordance with recent experiments in BSCCO performed in the second peak region
of the phase diagram (Portier et al, 2001), the relaxation strongly depends on
the initial conditions and is extremely slow. We investigate the dependence on
the pinning center density and the perturbation applied. We compare the
measurements to recent findings in tapped granular matter and we interpret our
results with a rather simple picture.Comment: 4 pages, 4 fig
Températures effectives et dynamique lente dans des systèmes modèles
PARIS-BIUSJ-Thèses (751052125) / SudocCentre Technique Livre Ens. Sup. (774682301) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF