Edge dependence of the Josephson current in the quantum Hall regime

Abstract

The observation of Josephson current in the quantum Hall regime has attracted considerable attention, revealing the coexistence of two seemingly incompatible phases: the quantum Hall and superconducting states. However, the mechanism underlying the Josephson current remains unclear because of the observed h/2e magnetic interference period and the lack of precisely quantized Hall plateaus. To address this issue, we investigate the edge dependence of the Josephson current in graphene Josephson junctions operating in the quantum Hall regime. By systematically comparing devices with native, etched, edge-free, and gate-defined edges, we demonstrate that the Josephson current is confined to the physical edges and is highly sensitive to specific edge configurations. Our findings provide direct evidence that counter-propagating quantum Hall edge states mediate Andreev bound states, enabling Josephson coupling. These results clarify the underlying mechanism of Josephson current in the quantum Hall regime and offer new strategies for engineering superconducting hybrid devices.

References in corpus (28)

• Topological insulators and superconductors
• Fault-tolerant quantum computation by anyons
• Boron nitride substrates for high-quality graphene electronics
• Non-Abelian Anyons and Topological Quantum Computation
• Bipolar supercurrent in graphene
• Majorana Zero Modes and Topological Quantum Computation
• Observation of the Fractional Quantum Hall Effect in Graphene
• Josephson Current and Noise at a Superconductor-Quantum Spin Hall Insulator-Superconductor Junction
• Exotic non-Abelian anyons from conventional fractional quantum Hall states
• Ballistic Josephson junctions in edge-contacted graphene
• Fractionalizing Majorana fermions: non-abelian statistics on the edges of abelian quantum Hall states
• Quantum oscillations of the critical current and high-field superconducting proximity in ballistic graphene
• Supercurrent in the quantum Hall regime
• Inducing Superconducting Correlation in Quantum Hall Edge States
• Quantum Hall effect in graphene with superconducting electrodes
• Charge accumulation at the boundaries of a graphene strip induced by a gate voltage: Electrostatic approach
• Ballistic graphene Josephson junctions from the short to the long regime
• Imaging work and dissipation in the quantum Hall state in graphene
• Andreev reflection in the fractional quantum Hall state
• A ballistic graphene superconducting microwave circuit
• Full control of quantum Hall supercurrent in a side gated graphene Josephson junction
• Evidence for chiral supercurrent in quantum Hall Josephson junctions
• Short Ballistic Josephson Coupling in Planar Graphene Junctions with Inhomogeneous Carrier Doping
• One-dimensional proximity superconductivity in the quantum Hall regime
• Upstream modes and antidots poison graphene quantum Hall effect
• Investigation of Supercurrent in the Quantum Hall Regime in Graphene Josephson Junctions
• Chiral Quasiparticle Tunneling Between Quantum Hall Edges in Proximity with a Superconductor
• Edge dependece of nonlocal transport in gapped bilayer graphene