LOWER CRITICAL DIMENSION OF THE XY SPIN-GLASS MODEL

We investigate the XY spin-glass model in two and three dimensions usi ng the domain-wall renormalization-group method. The results for syste ms of linear sizes up to L = 12 (2D) and L = 8 (3D) strongly suggest t hat the lower critical dimension for spin-glass ordering may be d(c) a pproximate to 3, rather than 4 as is commonly believed. Our 3D data fa vor the scenario of a low but finite spin-glass ordering temperature b elow the chiral transition, but they are also compatible with the syst em being at or slightly below its lower critical dimension.