{ "id": "1801.09779", "version": "v1", "published": "2018-01-29T22:05:17.000Z", "updated": "2018-01-29T22:05:17.000Z", "title": "Multicritical point on the de Almeida-Thouless line in spin glasses in $d>6$ dimensions", "authors": [ "M. A. Moore", "N. Read" ], "comment": "5 pages", "categories": [ "cond-mat.stat-mech", "cond-mat.dis-nn" ], "abstract": "The de Almeida-Thouless (AT) line in Ising spin glasses is the phase boundary in the temperature $T$ and magnetic field $h$ plane below which replica symmetry is broken. Using perturbative renormalization group (RG) methods, we show that when the dimension $d$ of space is just above $6$ there is a multicritical point (MCP) on the AT line, which separates a low-field regime, in which the critical exponents have mean-field values, from a high-field regime where the RG flows run away to infinite coupling strength; as $d$ approaches $6$ from above, the location of the MCP approaches the zero-field critical point exponentially in $1/(d-6)$. Thus on the AT line perturbation theory for the critical properties breaks down at sufficiently large magnetic field even above $6$ dimensions, as well as for all non-zero fields when $d\\leq 6$ as was known previously. We calculate the exponents at the MCP to first order in $\\varepsilon=d-6>0$. The fate of the MCP as $d$ increases from just above 6 to infinity is not known.", "revisions": [ { "version": "v1", "updated": "2018-01-29T22:05:17.000Z" } ], "analyses": { "keywords": [ "spin glasses", "multicritical point", "almeida-thouless line", "rg flows run away", "sufficiently large magnetic field" ], "note": { "typesetting": "TeX", "pages": 5, "language": "en", "license": "arXiv", "status": "editable" } } }