Critical Scaling of Extended Power Law I-V Isotherms near Vortex Glass Transition

Abstract

In view of the question about the vortex glass theory of the freezing of disordered vortex matter raised by recent experimental observations we reinvestigate the critical scaling of high $T_c$ superconductors. We find that dc current-voltage characteristic of mixed state superconductors has the general form of extended power law which is based on the Ginzburg-Landau (GL) functional in the similar way as the vortex glass theory. Isotherms simulated from this nonlinear equation fit the experimental I-V data of Strachan et al.[Phys.Rev.Lett. 87, 067007 (2001)]. The puzzling question of the derivative plot for the I-V curves and the controversy surrounding the values of critical exponents are also discussed.

4 pages, 7 figures; title changed, abstract rewritten, two main equations changed, one figure replaced, one figure slightly modified, some sentences changed, submitted to Phys.Rev.Lett