Phase diffusion and suppression of the supercurrent by quantum-mechanical fluctuations of the Josephson plasma

Kurt Gloos; Frithjof Anders

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arXiv · cond-mat/9905294

Phase diffusion and suppression of the supercurrent by quantum-mechanical fluctuations of the Josephson plasma

Kurt Gloos·Frithjof Anders

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Abstract

The RCSJ model of resistively and capacitively shunted Josephson junctions is used to describe superconducting point contacts over a wide range of resistances up to the metallic -- tunneling transition. Their small dynamic capacitance of order $C = 0.1 $fF due to the point-contact geometry results in a huge plasma frequency. The critical current is then strongly suppressed and the contact resistance becomes finite because of quantum-mechanical zero-point fluctuations of the Josephson plasma and the rather large escape rate out of the zero-voltage state due to quantum tunneling. We test the predictions of the RCSJ model on the classical superconductors lead, indium, aluminum, and cadmium.

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Kurt Gloos, Frithjof Anders. 1999-06-04. Phase diffusion and suppression of the supercurrent by quantum-mechanical fluctuations of the Josephson plasma. https://arxiv.org/abs/cond-mat/9905294

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