We present simulations of the transport properties of superconductors at the
transition from the Bragg glass (BG) to the vortex glass (VG) phase. We study
the frustrated anisotropic 3D XY model with point disorder, which has been
shown to have a first order transition as a function of the intensity of
disorder. We add an external current to the model and we obtain current-voltage
curves as a function of disorder at a low temperature. We find that the
in-plane critical current has a steep increase at the BG-VG transition, while
the c-axis critical current has a discontinous jump down, this later result in
agreement with the first-order character of the transition.Comment: 4 pages, 5 figures. Introduction changed. Accepted for publication in
Physical Review Letter