Detailed structure of configuration space and its importance on ergodic separation of ±J Ising lattices.

E. E. VOGEL; A. J. RAMIREZ-PASTOR; F. NIETO

PHYSICA A - STATISTICAL AND THEORETICAL PHYSICS

Elsevier

Año: 2002 vol. 310 p. 384 - 396

0378-4371

A complete andexact characterization of the con$guration space of 2-D ±J Ising lattices is performed. A new algorithm is introduced here representing advantages for reaching all states for small samples andd oing a non-biasedsampling of groundstates for larger samples. We report e4cient procedures to $ndall groundstates groupedin local ensembles of groundstates (LEGs) andalso a convenient way of storing andcomparing states. Properties of such LEGs di7er from some approximate descriptions reported in the literature. The onset of lattice size dependence of properties is discussed. Four di7erent ways of performing ergodic separation are used to calculate order parameters. The most signi$cant way of doing ergodic separation requires previous classi$cation of states in LEGs.±J Ising lattices is performed. A new algorithm is introduced here representing advantages for reaching all states for small samples andd oing a non-biasedsampling of groundstates for larger samples. We report e4cient procedures to $ndall groundstates groupedin local ensembles of groundstates (LEGs) andalso a convenient way of storing andcomparing states. Properties of such LEGs di7er from some approximate descriptions reported in the literature. The onset of lattice size dependence of properties is discussed. Four di7erent ways of performing ergodic separation are used to calculate order parameters. The most signi$cant way of doing ergodic separation requires previous classi$cation of states in LEGs.