Fractional Josephson effect in nonuniformly strained graphene

Abstract

Nonuniform strain distributions in a graphene lattice can give rise to uniform pseudomagnetic fields and associated pseudo-Landau levels without breaking time-reversal symmetry. We demonstrate that by inducing superconductivity in a nonuniformly strained graphene sheet, the lowest pseudo-Landau levels split by a pairing gap can be inverted by changing the sign of the pairing potential. As a consequence of this inversion, we predict that a Josephson $\pi$ junction deposited on top of a strained graphene sheet exhibits one-dimensional gapless modes propagating along the junction. These gapless modes mediate single electron tunneling across the junction, giving rise to the $4\pi$-periodic fractional Josephson effect.

6 pages, 4 figures

References in corpus (9)

• The electronic properties of graphene
• Topological Field Theory of Time-Reversal Invariant Insulators
• Bipolar supercurrent in graphene
• Electron fractionalization in two-dimensional graphenelike structures
• Exotic non-Abelian anyons from conventional fractional quantum Hall states
• Fractionalizing Majorana fermions: non-abelian statistics on the edges of abelian quantum Hall states
• Supercurrent in the quantum Hall regime
• Flat band superconductivity in strained Dirac materials
• Spin-triplet supercurrent carried by quantum Hall edge states through a Josephson junction

Cited by in corpus (8)

• Electronic Structure Theory of Strained Two-Dimensional Materials with Hexagonal Symmetry
• Proximity coupling in superconductor-graphene heterostructures
• Quantum Hall response to time-dependent strain gradients in graphene
• Quantum oscillations and Dirac-Landau levels in Weyl superconductors
• Phase diagrams and edge-state transitions in graphene with spin-orbit coupling and magnetic and pseudomagnetic fields
• Proximity-induced superconductivity in Landau-quantized graphene monolayers
• New supercurrent pattern in quantum point contact with strained graphene nanoribbon
• Helical superconducting edge modes from pseudo-Landau levels in graphene