 Author

S. Guruswamy
A. LeClair
A. Ludwig  Year
 2000
 Title
 gl(NN) SuperCurrent Algebras for Disordered Dirac Fermions in Two Dimensions
 Journal
 Nuclear Physics B
 Volume
 583
 Pages (fromto)
 475512
 Document type
 Article
 Faculty
 Faculty of Science (FNWI)
 Institute
 Institute for Theoretical Physics Amsterdam (ITFA)
 Abstract

We consider the nonhermitian 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 particlehole symmetry in every realization of disorder. Case (A) is in addition timereversal invariant, and can also be interpreted as the randomfield XY Statistical Mechanics model in two dimensions. The supersymmetric approach to disorder averaging results in currentcurrent perturbations of $gl(NN)$ supercurrent algebras. Special properties of the $gl(NN)$ algebra allow the exact computation of the betafunctions, and of the correlation functions of all currents. One of them is the EdwardsAnderson order parameter. The theory is `nearly conformal' and possesses a scaleinvariant 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 GadeWegner (RandomFlux) universality class, using a $GL(NN;C)/U(NN)$ sigma model, as well as its $PSL(NN)$ variant, and a corresponding generalized random XY model. For $N=1$ the sigma model is shown to be identical to the currentcurrent perturbation. For the delocalization transitions (case (A) and (B)) a density of states, diverging at zero energy, is found.
 URL
 go to publisher's site
 Language
 Undefined/Unknown
 Permalink
 http://hdl.handle.net/11245/1.175477
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