Through Kaleidoscope Eyes Spin Glasses Experimental Results and Theoretical Concepts

A spin glass describes a system of spins on a lattice (or a crystal) where the interactions are frustrated as well as disordered. Studying such systems presents many theoretical difficulties, but over the last twenty years considerable advances have been made. In this paper I will discuss some of the experimental results that motivated theorists and some of the concepts that were developed to deal with the physics of disordered system. Specifically, the Edwards-Anderson model and their formulation the the relevant order parameters will be discussed as well as the Sherrington-Kirkpatrick model which gave a mean field, exactly soluble version of Edwards-Anderson model. I will also talk about Parisi’s solution and the non-trivial ergodicity breaking that occurs in spin glasses. Spin glasses and the physics of disordered systems have found a wide range of applicability and it is the goal to review some of the experimental features and theoretical concepts developed.