Noise rectification by a superconducting loop with two weak links

Abstract

We consider a superconducting loop with two weak links that encloses a magnetic flux. The weak links are unequal and are treated as Josephson junctions with non-sinusoidal phase dependence. We devise a model that takes into account the fluctuation of the critical currents, due to the fluctuations of the order parameter in the weak links. These fluctuations are important near the onset of superconductivity; in this regime they may significantly weaken and eventually disconnect the superconducting loop. As a consequence of these fluctuations and of the resistive noise in the junctions, the average dc voltage does not vanish. Our model can be easily extended to provide a qualitative description of a recent experiment.

version accepted by PRB

References in corpus (8)

• Brownian motors: noisy transport far from equilibrium
• Voltage rectification by a SQUID ratchet
• Superconducting Fluxon Pumps and Lenses
• Collective Interaction-Driven Ratchet for Transporting Flux Quanta
• Ratchet potential for fluxons in Josephson-Junction arrays
• Ratchet effect in dc SQUIDs
• Induction of dc voltage, proportional to the persistent current, by external ac current on system of inhomogeneous superconducting loops
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• Thermo-charged capacitors and the Second Law of Thermodynamics
• Observation of large $h/2e$ and $h/4e$ oscillations in a proximity dc superconducting quantum interference device
• On the exploitability of thermo-charged capacitors
• Voltage rectification effects in mesoscopic superconducting triangles: experiment and modelling
• Supercurrent fluctuations in short filaments