Negative magnetoresistance and phase slip process in superconducting nanowires

Abstract

We argue that the negative magnetoresistance of superconducting nanowires, which was observed in recent experiments, can be explained by the influence of an external magnetic field on the critical current of the phase slip process. We show that suppression of the order parameter in bulk superconductors made by an external magnetic field can lead to an enhancement of both the first Ic1 and second Ic2 critical currents of the phase slip process in nanowires. Another mechanism of an enhancement of Ic1 can come from decreasing the decay length of the charge imbalance λQ at weak magnetic fields because Ic1 is inversely proportional to λQ. We show that both mechanisms of the enhancement of the first critical current originate from the enhancement of the intrinsic dissipation of the phase slip process. That effect leads to a suppression of the rate of the thermoactivated (and probably quantum fluctuated) phase slips and results in decreasing the fluctuated resistance.

Source-reported materials — not catalogue approval

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