2003/01/16 by Petter Holme, Petter Minnhagen, Beom Jun Kim
Physics and Astronomy · #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.67.104510
published as Phys. Rev. B 67, 104510 (2003). · 5 pages in two-column form, 4 figures. To appear in PRB
arxiv created 2003/01/16 · arxiv updated 2009/11/30
The two-dimensional random gauge \xy model, where the quenched random variables are magnetic bond angles uniformly distributed within [-rπ, rπ] (0 ≤ r ≤ 1), is studied via Monte Carlo simulations. We investigate the phase diagram in the plane of the temperature T and the disorder strength r, and infer, in contrast to a prevailing conclusion in many earlier studies, that the system is superconducting at any disorder strength r for sufficiently low T. It is also argued that the superconducting to normal transition has different nature at weak disorder and strong disorder: termed Kosterlitz-Thouless (KT) type and non-KT type, respectively. The results are compared to earlier works.