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arXiv · 1702.04826

Fractional Josephson effect in nonuniformly strained graphene

Shu-Ping Lee·Debaleena Nandi·Frank Marsiglio·Joseph Maciejko
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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 $π$ 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 $4π$-periodic fractional Josephson effect.

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Shu-Ping Lee, Debaleena Nandi, Frank Marsiglio, Joseph Maciejko. 2017-05-24. Fractional Josephson effect in nonuniformly strained graphene. https://doi.org/10.1103/physrevb.95.174517

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