doi:10.1073/pnas.1203295109engAlvarez Baños, R.Cruz, A.Fernandez, L.A.Gil-Narvion, J.M.Gordillo-Guerrero, A.Guidetti, M.Iñiguez, D.Maiorano, A.Marinari, E.Martin-Mayor, V.Monforte-Garcia, J.Muñoz-Sudupe, A.Navarro, D.Parisi, G.Perez-Gaviro, S.Ruiz-Lorenzo, J.J.Schifano, S.F.Seoane, B.Tarancon, A.Tellez, P.Tripiccione, R.Yllanes, D.Thermodynamic glass transition in a spin glass without time-reversal symmetryART-2012-82188Spin glasses are a longstanding model for the sluggish dynamics that appear at the glass transition. However, spin glasses differ from structural glasses in 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 behavior 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.2012http://zaguan.unizar.es/record/15210010.1073/pnas.1203295109http://zaguan.unizar.es/record/152100oai:zaguan.unizar.es:152100info:eu-repo/grantAgreement/ES/MICINN/FIS2009-12648-C03-02info:eu-repo/grantAgreement/ES/MICINN/FIS2010-16587info:eu-repo/grantAgreement/ES/MICINN/TEC2010-19207Proceedings of the National Academy of Sciences of the United States of America 109, 17 (2012), 6452-6456by-nc-ndhttps://creativecommons.org/licenses/by-nc-nd/4.0/deed.esinfo:eu-repo/semantics/openAccess