Ballistic and diffusive regimes in current-phase relations of graphene SNS heterojunctions

ORAL

Abstract

Current-phase relations (CPRs) are an indirect measurement of the energy distribution of phase-coherent modes in Josephson junctions through the spectral supercurrent near equilibrium, probing low-energy excitations not accessible by transport. We report on planned experimental measurements of the CPRs of gated, high-mobility (~10$^5$ cm$^2$/Vs) single-layer graphene SNS heterojunctions in ring geometries with superconducting MoRe alloy contacts, inductively read out with a scanning superconducting quantum interference device (SQUID) magnetometer. The graphene layers are encapsulated on both sides with hexagonal-BN (h-BN). We will address the CPR dependence on experimentally tunable parameters (temperature, carrier density, and channel length), and possible crossovers between the ballistic and diffusive regimes.

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Authors

  • Philip Kratz

    • Stanford University

  • Francois Amet

    • Duke University

  • Christopher Watson

    • Stanford University

  • Kathryn Moler

    • Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory

  • Chung Ke

    • Duke University, Durham

  • Ivan Borzenets

    • University of Tokyo

  • Kenji Watanabe

    • National Institute for Materials Science

  • Takashi Taniguchi

    • National Institute for Materials Science

  • Russell Deacon

    • (CEMS), RIKEN

  • Michihisa Yamamoto

    • University of Tokyo

  • Yuriy Bomze

    • Duke University

  • Seigo Tarucha

    • University of Tokyo

  • Gleb Finkelstein

    • Duke University