https://doi.org/10.1007/s100510070233
Model glasses coupled to two different heat baths
1
Yerevan Physics Institute, Alikhanian Brothers St. 2,
Yerevan 375036, Armenia
2
Institute of Theoretical Physics,
University of Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam,
The Netherlands
3
Department of Physics and Astronomy, University of Amsterdam,
Valckenierstraat 65, 1018 XE Amsterdam,
The Netherlands
Received:
12
July
1999
Revised:
8
December
1999
Published online: 15 July 2000
In a p-spin interaction spherical spin-glass model both the spins and the couplings are allowed to change with time. The spins are coupled to a heat bath with temperature T, while the coupling constants are coupled to a bath having temperature TJ. In an adiabatic limit (where relaxation time of the couplings is much larger that of the spins) we construct a generalized two-temperature thermodynamics. It involves entropies of the spins and the coupling constants. The application for spin-glass systems leads to a standard replica theory with a non-vanishing number of replicas, n=T/TJ. For p> 2 there occur at low temperatures two different glassy phases, depending on the value of n. The obtained first-order transitions have positive latent heat, and positive discontinuity of the total entropy. This is an essentially non-equilibrium effect. The dynamical phase transition exists only for n< 1. For p=2 correlation of the disorder (leading to a non-zero n) removes the known marginal stability of the spin glass phase. If the observation time is very large there occurs no finite-temperature spin glass phase. In this case there are analogies with the non-equilibrium (aging) dynamics. A generalized fluctuation-dissipation relation is derived.
PACS: 64.70.Pf – Glass transitions / 05.70.Ln – Nonequilibrium and irreversible thermodynamics / 75.10.Nr – Spin-glass and other random models
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000