title: Nature of ergodicity breaking in ising spin glasses as revealed by correlation function spectral properties
abstract: In this Letter we address the nature of broken ergodicity in the low temperature phase of Ising spin glasses by examining spectral properties of spin correlation functions C(ij) identical with<S(i)S(j)>. We argue that more than one extensive [i.e., O(N)] eigenvalue in this matrix signals replica symmetry breaking. Monte Carlo simulations of the infinite-range Ising spin-glass model, above and below the Almeida-Thouless line, support this conclusion. Exchange Monte Carlo simulations for the short-range model in four dimensions find a single extensive eigenvalue and a large subdominant eigenvalue consistent with droplet model expectations.
authors.affiliation: Department of Physics, University of Tennessee, Knoxville, Tennessee 37996 and Department of Physics, Indiana University, Bloomington, Indiana 47405, USA.
authors.initials: J
authors.lastname: Sinova
authors.initials: G
authors.lastname: Canright
authors.initials: AH
authors.lastname: MacDonald