Symmetric Langevin spin glass dynamics

Stochastic Spin Dynamics & Langevin-Landau-Gilbert Simulations

Here I discuss the dynamics of microscopic systems, primarily for spin models, in thermal equilibrium, where the temperature causes random forces or torques, which are in competition with a damping force. This includes summarizing Langevin dynamics and finding methods for integrating the Landau-Gilbert equation of micromagnetics in time, with damping & temperature. The goal is to understand how...

Aging and Spin-glass Dynamics

We survey the recent mathematical results about aging in certain simple disordered models. We start by the Bouchaud trap model. We then survey the results obtained for simple models of spin-glass dynamics, like the REM (the Random Energy Model, which is well approximated by the Bouchaud model on the complete graph), then the spherical Sherrington-Kirkpatrick model. We will insist on the differe...

Instantons in the Langevin dynamics: an application to spin glasses.

Instantons in the Langevin dynamics: an application to spin glasses. Abstract We develop a general technique to calculate the probability of transitions over the barriers in spin-glasses in the framework of the dynam-ical theory. We use Lagrangian formulation of the instanton dynamics in which the transitions are represented by instantons. We derive the full set of the equations that determine ...

Fluctuations in finite dimensional spin-glass dynamics

Aging dynamics of the Heisenberg spin glass

We numerically study the nonequilibrium dynamics of the three-dimensional Heisenberg Edwards-Anderson spin glass following a sudden quench to its low-temperature phase. The subsequent aging behavior of the system is analyzed in detail, and the scaling behavior of various space-time correlation functions is investigated for both spin and chiral degrees of freedom. We carefully compare our result...