Europhys. Lett.
Volume 69, Number 2, January 2005
Page(s) 256 - 262
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 17 December 2004
Europhys. Lett., 69 (2), pp. 256-262 (2005)
DOI: 10.1209/epl/i2004-10320-5

Topological order in the (2+1)D compact lattice superconductor

A. Vestergren1, J. Lidmar1 and T. H. Hansson2

1  Department of Physics, Royal Institute of Technology, AlbaNova SE-106 91 Stockholm, Sweden
2  Fysikum, Stockholm University, AlbaNova - SE-106 91 Stockholm, Sweden

received 13 September 2004; accepted 4 November 2004
published online 17 December 2004

We study topological aspects of a compact lattice superconductor, and show that the characteristic energy splitting, $\Delta$, between almost degenerate ground states, is simply related to a novel order parameter $\tilde{W}$, which is closely related to large Wilson loops. Using Monte Carlo methods, we study the scaling properties of $\tilde{W}$ close to the deconfining phase transition, and conclude that $\Delta\sim e^{-L/\xi}$, where L is the size of the system, thus giving quantitative support to the vortex tunneling scenario proposed by Wen.

74.20.-z - Theories and models of superconducting state.
11.15.Ha - Lattice gauge theory.
71.10.Hf - Non-Fermi-liquid ground states, electron phase diagrams and phase transitions in model systems.

© EDP Sciences 2005