arXiv subjects
Publications and source records attributed to T. Aspelmeier.
The overlap length of a three-dimensional Ising spin glass on a cubic lattice with Gaussian interactions has been estimated numerically by transfer matrix methods and within a Migdal-Kadanoff renormalization group scheme. We find that the overlap length is large, explaining why it has been difficult to observe spin glass chaos in numerical simulations and experiment.
The time evolution of structure factors in the disordering process of an initially phase separated lattice depends crucially on the microscopic mechanism which drives the disordering, such as Kawasaki dynamics or vacancy mediated disordering. Monte Carlo (MC) simulations show unexpected ``dips'' in the structure factors, which mean-field theory completely fails to capture. The disordering via vacancies is slower by a surprisingly large constant factor compared to Kawasaki dynamics. A phenomenological model is introduced in order to understand the dips, and an analytical solution of Kawasaki dynamics is derived, in excellent agreement with simulations. An outline is given on how to extend the analytical solution to the more complicated case of a wandering vacancy.