{ "id": "cond-mat/9909143", "version": "v1", "published": "1999-09-09T22:57:24.000Z", "updated": "1999-09-09T22:57:24.000Z", "title": "gl(N|N) Super-Current Algebras for Disordered Dirac Fermions in Two Dimensions", "authors": [ "S. Guruswamy", "A. LeClair", "A. W. W. Ludwig" ], "comment": "LaTeX, 40 pages", "journal": "Nucl.Phys. B583 (2000) 475-512", "doi": "10.1016/S0550-3213(00)00245-5", "categories": [ "cond-mat.mes-hall", "cond-mat.dis-nn", "cond-mat.stat-mech", "hep-th" ], "abstract": "We consider the non-hermitian 2D Dirac Hamiltonian with (A): real random mass, imaginary scalar potential and imaginary gauge field potentials, and (B) arbitrary complex random potentials of all three kinds. In both cases this Hamiltonian gives rise to a delocalization transition at zero energy with particle-hole symmetry in every realization of disorder. Case (A) is in addition time-reversal invariant, and can also be interpreted as the random-field XY Statistical Mechanics model in two dimensions. The supersymmetric approach to disorder averaging results in current-current perturbations of $gl(N|N)$ super-current algebras. Special properties of the $gl(N|N)$ algebra allow the exact computation of the beta-functions, and of the correlation functions of all currents. One of them is the Edwards-Anderson order parameter. The theory is `nearly conformal' and possesses a scale-invariant subsector which is not a current algebra. For N=1, in addition, we obtain an exact solution of all correlation functions. We also study the delocalization transition of case (B), with broken time reversal symmetry, in the Gade-Wegner (Random-Flux) universality class, using a GL(N|N;C)/U(N|N) sigma model, as well as its PSL(N|N) variant, and a corresponding generalized random XY model. For N=1 the sigma model is shown to be identical to the current-current perturbation. For the delocalization transitions (case (A) and (B)) a density of states, diverging at zero energy, is found.", "revisions": [ { "version": "v1", "updated": "1999-09-09T22:57:24.000Z" } ], "analyses": { "keywords": [ "disordered dirac fermions", "super-current algebras", "generalized random xy model", "xy statistical mechanics model", "delocalization transition" ], "tags": [ "journal article" ], "publication": { "publisher": "Elsevier", "journal": "Nucl. Phys. B" }, "note": { "typesetting": "LaTeX", "pages": 40, "language": "en", "license": "arXiv", "status": "editable", "inspire": 506923 } } }