Geometrical aspects of aging and rejuvenation in the Ising spin glass: A numerical study
Abstract
We present a comprehensive study of nonequilibrium phenomena in the low-temperature phase of the Edwards-Anderson Gaussian spin glass in three and four spatial dimensions. Many effects can be understood in terms of a time-dependent coherence length lT such that length scales smaller than lT are equilibrated, whereas larger length scales are essentially frozen. The time and temperature dependences of lT are found to be compatible with critical power-law dynamical scaling for small times and high temperatures, crossing over to an activated logarithmic growth for longer times and lower temperatures, in agreement with recent experimental results. The activated regime is governed by a ``barrier exponent'' ψ which we estimate to be ψ~1.0 and 2.3 in three and four dimensions, respectively. We observe the rejuvenation and memory effects in the four-dimensional sample, which, we argue, is unrelated to ``temperature chaos.'' Our discussion in terms of length scales allows us to address several experimentally relevant issues, such as superaging versus subaging effects, the role of a finite cooling rate, or the so-called Kovacs effect.
- Publication:
-
Physical Review B
- Pub Date:
- August 2002
- DOI:
- 10.1103/PhysRevB.66.054404
- arXiv:
- arXiv:cond-mat/0202069
- Bibcode:
- 2002PhRvB..66e4404B
- Keywords:
-
- 75.10.Nr;
- 05.70.Ln;
- 75.40.Mg;
- Spin-glass and other random models;
- Nonequilibrium and irreversible thermodynamics;
- Numerical simulation studies;
- Condensed Matter - Statistical Mechanics;
- Condensed Matter - Disordered Systems and Neural Networks
- E-Print:
- Version accepted for publication - Physical Review B