RESISTIVE HYSTERESIS AND NONLINEAR I-V CHARACTERISTICS AT THE FIRST-ORDER MELTING OF THE ABRIKOSOV VORTEX LATTICE

We study a three-dimensional network of Josephson junctions in a magne tic field, which undergoes a first-order melting transition of the tri angular vortex lattice. We perform a Langevin dynamics calculation of the resistance and current-voltage (I-V) characteristics. We find hyst eresis in the resistance as a function of temperature as measured in u ntwinned YBa2Cu3O7, Close to the melting temperature the I-V curves ar e S shaped with hysteresis and show a melting transition when increasi ng the current, driven by the blowing out of current nucleated vortex loops.