6533b825fe1ef96bd1281dfe
RESEARCH PRODUCT
Kinetics of Ordered Phases in Finite Spin Systems
P MonachesiBernardo SpagnoloSergio CiuchiF. De Pasqualesubject
PhysicsSpin glassCondensed matter physicsSpin polarizationSpinsRelaxation (NMR)magnetic phase transitionsCondensed Matter PhysicsInstabilitygeneral models of magnetic orderingAtomic and Molecular Physics and Opticsnumerical models of phase transitionsSpherical modelAmplitudeMathematical Physicsmagnetic phase transitions; general models of magnetic ordering; numerical models of phase transitionsSpin-½description
We study the growth of the ordered phase in a spin system of finite size suddenly brought below the transition temperature. Such a growth is driven by the instability of the mode corresponding to the largest eigenvalue of the interaction matrix. The relaxation occurs through different regimes according to whether the unstable mode has a negligible or macroscopic amplitude. One regime is characterised by dynamical scaling properties whereas in the other we can distinguish the growth to a macroscopic amplitude followed by rare transitions from one equilibrium amplitude to another. The analysis is carried out in the framework of a dynamical generalisation of the spherical model assuming non-random and random interactions among the spins. Differences between spin glass and ferromagnetic behaviour are pointed out.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1989-01-01 | Physica Scripta |