The Eigenvalue Analysis of the Density Matrix of 4D Spin Glasses   Supports Replica Symmetry Breaking
  We present a general and powerful numerical method useful to study the density matrix of spin models. We apply the method to finite dimensional spin glasses, and we analyze in detail the four dimensional Edwards-Anderson model with Gaussian quenched random couplings. Our results clearly support the existence of replica symmetry breaking in the thermodynamical limit. 
L. Correale, E. Marinari and V. Martin-Mayor