{ "id": "1506.07128", "version": "v1", "published": "2015-06-23T18:38:18.000Z", "updated": "2015-06-23T18:38:18.000Z", "title": "Introduction to Mean-Field Theory of Spin Glass Models", "authors": [ "Václav Janiš" ], "comment": "28 pages, Lecture Notes for the Autumn School on Correlated Electrons, J\\\"ulich, 2015 (http://www.cond-mat.de/events/correl15). arXiv admin note: text overlap with arXiv:1501.01653", "categories": [ "cond-mat.dis-nn" ], "abstract": "We discuss the mean-field theory of spin-glass models with frustrated long-range random spin exchange. We analyze the reasons for breakdown of the simple mean-field theory of Sherrington and Kirkpatrick. We relate the replica-symmetry breaking to ergodicity breaking and use the concept of real replicas to restore thermodynamic homogeneity of the equilibrium free energy in a replicated phase space. Embedded replications of the spin variables result in a set of hierarchical free energies and overlap susceptibilities between replica hierarchies as order parameters. The limit to infinite number of replica hierarchies leads to the Parisi solution with a continuous replica-symmetry breaking. We present a closed-form representation of the Parisi mean-field theory that is independent from stability of solutions with finite-many replica hierarchies. Hence, solutions with continuous and discrete replica-symmetry breaking can coexist. We demonstrate the construction of the spin-glass mean-field solutions via real replicas on three spin-glass models: Ising, Potts and p-spin. An asymptotic expansion in each model is used to demonstrate various types of the transition from the paramagnetic to the glassy phase.", "revisions": [ { "version": "v1", "updated": "2015-06-23T18:38:18.000Z" } ], "analyses": { "keywords": [ "mean-field theory", "spin glass models", "replica hierarchies", "introduction", "spin-glass models" ], "tags": [ "lecture notes" ], "note": { "typesetting": "TeX", "pages": 28, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv150607128J" } } }