Abstract
Using a functional renormalization group (RG) method, we reexamine the glass phase of the two-dimensional random-field sine Gordon model. It is described by a line of fixed points with a super-roughening amplitude as temperature is varied. By speculating that this line is identical for all to the one found in disordered free-fermion models via exact results from “nearly conformal” field theory, one would predict , contradicting numerics. We point out that this result may be related to failure of dimensional reduction, and that a functional RG method incorporating higher harmonics and nonanalytic operators predicts a nonzero which compares reasonably well with numerics.
- Received 13 December 2006
DOI:https://doi.org/10.1103/PhysRevB.75.184401
©2007 American Physical Society