%0 Journal Article
%T Thermodynamic glass transition in a spin glass without time-reversal symmetry
%A Janus Collaboration
%A R. A. Ba£żos
%A A. Cruz
%A L. A. Fernandez
%A J. M. Gil-Narvion
%A A. Gordillo-Guerrero
%A M. Guidetti
%A D. I£żiguez
%A A. Maiorano
%A E. Marinari
%A V. Martin-Mayor
%A J. Monforte-Garcia
%A A. Mu£żoz Sudupe
%A D. Navarro
%A G. Parisi
%A S. Perez-Gaviro
%A J. J. Ruiz-Lorenzo
%A S. F. Schifano
%A B. Seoane
%A A. Tarancon
%A P. Tellez
%A R. Tripiccione
%A D. Yllanes
%J Physics
%D 2012
%I arXiv
%R 10.1073/pnas.1203295109
%X Spin glasses are a longstanding model for the sluggish dynamics that appears at the glass transition. However, spin glasses differ from structural glasses for a crucial feature: they enjoy a time reversal symmetry. This symmetry can be broken by applying an external magnetic field, but embarrassingly little is known about the critical behaviour of a spin glass in a field. In this context, the space dimension is crucial. Simulations are easier to interpret in a large number of dimensions, but one must work below the upper critical dimension (i.e., in d<6) in order for results to have relevance for experiments. Here we show conclusive evidence for the presence of a phase transition in a four-dimensional spin glass in a field. Two ingredients were crucial for this achievement: massive numerical simulations were carried out on the Janus special-purpose computer, and a new and powerful finite-size scaling method.
%U http://arxiv.org/abs/1202.5593v1