Pairing of holes via vortex/antivortex attraction in doped La 2-x(Sr)xCuO4

Abstract

The consequences of delocalised magnetic frustration in the pure antiferromagnetic XY (n=2) spin system are studied numerically. This frustration is found to enhance significantly the formation of vortex excitations, which tend to bind antivortices below the Kosterlitz-Thouless transition temperature. We find a net attraction between frustrated plaquettes mediated by the attraction between the vortices. Applied to the understanding of high temperature superconducting materials, like La 2−x (Sr) x CuO 4 , this can serve as a real space pairing mechanism with a high binding energy between the holes, induced by doping. There are common features between this pairing model and the «spinon-holon» picture, which may provide a link between these different approaches