Novel order parameter to describe the critical behavior of Ising spin glass models

A novel order parameter Phi for spin glasses is defined based oil topological criteria and with a clear physical interpretation. Phi is first investigated for well known magnetic systems and then applied to the Edwards-Anderson +/- J model oil a square lattice, comparing its properties with the usual q order parameter. Finite size scaling procedures are performed. Results and analyses based on Phi confirm a zero temperature phase transition and allow to identify the low temperature phase. The advantages of Phi are brought out and its physical meaning is established. (c) 2005 Elsevier B.V. All rights reserved.