Stochastic transitions between phase-locked steady states in RF-irradiated graphene Josephson junctions
ORAL
Abstract
We investigate the Shapiro steps in a graphene-based Josephson junction with large gap MoRe leads. A wide variety of patterns are obtained, depending on the carrier density, temperature, RF frequency, and magnetic field. A particularly interesting regime of intermediate driving power is identified, in which the zero voltage state becomes unstable even at zero bias, and the junction spontaneously develops a voltage V=±~hf/2e, which could persist for a several hours. We study the switching time between the ±~hf/2e states as a function of applied power and temperature, and find a novel non-monotonic regime, in which the switching time between these attractors demonstrates a pronounced minimum at intermediate temperatures.
*Measurements conducted by T.L. and E.A were supported by Division of Materials Sciences and Engineering, Office of Basic Energy Sciences, U.S. Department of Energy, under Award No. DE- SC0002765. M-T.W. and A.S. performed lithographic fabrication and characterization of the samples with the support of NSF awards ECCS-1610213 and DMR-1743907. L.Z. and G.F. were supported by ARO Award W911NF16-1-0122. H.L. and F.A. acknowledge the ARO Award W911NF-16-1-0132.
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Presenters
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Trevyn Larson
- Duke University
- Department of Physics, Duke University
- Physics, Duke University