On the Relevance of Disorder for Dirac Fermions with Imaginary Vector Potential
Abstract
Description
We consider the effects of disorder in a Dirac-like Hamiltonian. In order to use conformal perturbation theory, we argue that one should consider disorder in an imaginary vector potential. This affects significantly the signs of the lowest order $β$eta functions. We present evidence for the existence of two distinct universality classes, depending on the relative strengths of the gauge field verses impurity disorder strengths. In one class all disorder is driven irrelevant by the gauge field disorder.
4 pages, 1 figure. New version has expanded and improved discussion of why one should consider an imaginary vector potential in a physical localization problem. Factors of 2 in beta functions corrected. References added
4 pages, 1 figure. New version has expanded and improved discussion of why one should consider an imaginary vector potential in a physical localization problem. Factors of 2 in beta functions corrected. References added