Effect of high-frequency magnetic fields on the dissipative vortex motion in the superconducting mixed state

We have studied the current-voltage characteristics in the mixed state of superconducting films of amorphous Mo3Si in a perpendicular magnetic field B0 + B1 sin ωt with B1 ≪ B0. Whereas for B1 = 0 a resistive voltage is observed only above the critical current Ic, for B1 > 0 perfectly ohmic behavior is found, starting already near zero current. Our experiments confirm that in this ohmic regime the dependence of the resistivity upon temperature and static field B0 is quantitatively related to the corresponding dependence of the critical current density jc in the films. Such behavior has been predicted in a simplified model we proposed recently. © 1997 Elsevier Science B.V.