Dynamical I-V Characteristics of SNS Junctions

Abstract

We have probed the switching dynamics of the Josephson critical current of a superconducting weak link by measuring its voltage/current characteristics while applying an ac current bias in the range 1-200 MHz. The weak link between two Nb reservoirs is formed by an mesoscopic Al wire above its critical temperature. We observe a dynamical phase transition as a function of the frequency and amplitude of the ac current. While at low frequency the transition driven by increasing the current bias is well described by the standard Kramers theory, at high frequency the switching histograms become hysteretic and much narrower than expected by thermal fluctuations. The crossover frequency between the two regimes is set by the electron-phonon interaction rate in the normal metal.

5 pages, 4 figures

References in corpus (5)

• Proximity DC squids in the long junction limit
• Supernarrow spectral peaks near a kinetic phase transition in a driven, nonlinear micromechanical oscillator
• Theory of Microwave-Assisted Supercurrent in Diffusive SNS Junctions
• Quantum cavity modes in spatially extended Josephson systems
• Origin of Hysteresis in a Proximity Josephson Junction

Cited by in corpus (4)

• Fluctuation-Dissipation in Thermoelectrics
• Stochastic thermal feedback in switching measurements of superconducting nanobridge caused by overheated electrons and phonons
• Slow electron-phonon relaxation controls the dynamics of the superconducting resistive transition
• Implementation of SNS thermometers into molecular devices for cryogenic thermoelectric experiments