Spin 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.
Thermodynamic glass transition in a spin glass without time-reversal symmetry / R. A., Banos; A., Cruz; L. A., Fernandez; J. M., Gil Narvion; A., Gordillo Guerrero; M., Guidetti; D., Iniguez; Maiorano, Andrea; Marinari, Vincenzo; V., Martin Mayor; J., Monforte Garcia; A., Munoz Sudupe; D., Navarro; Parisi, Giorgio; S., Perez Gaviro; J. J., Ruiz Lorenzo; S. F., Schifano; B., Seoane; A., Tarancon; P., Tellez; R., Tripiccione; D., Yllanes. - In: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA. - ISSN 0027-8424. - 109:17(2012), pp. 6452-6456. [10.1073/pnas.1203295109]
Thermodynamic glass transition in a spin glass without time-reversal symmetry
MAIORANO, Andrea;MARINARI, Vincenzo;PARISI, Giorgio;
2012
Abstract
Spin 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
