Superfluid weight and Berezinskii-Kosterlitz-Thouless transition temperature of twisted bilayer graphene
Julku, A., Peltonen, T. J., Liang, L., Heikkilä, T. T., & Törmä, P. (2020). Superfluid weight and Berezinskii-Kosterlitz-Thouless transition temperature of twisted bilayer graphene. Physical Review B, 101(6), Article 060505. https://doi.org/10.1103/PhysRevB.101.060505
Published inPhysical Review B
© 2020 American Physical Society
We study superconductivity of twisted bilayer graphene with local and nonlocal attractive interactions. We obtain the superfluid weight and Berezinskii-Kosterlitz-Thouless (BKT) transition temperature for microscopic tight-binding and low-energy continuum models. We predict qualitative differences between local and nonlocal interaction schemes which could be distinguished experimentally. In the flat-band limit where the pair potential exceeds the band width we show that the superfluid weight and BKT temperature are determined by multiband processes and quantum geometry of the band.
PublisherAmerican Physical Society
ISSN Search the Publication Forum2469-9950
Publication in research information system
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Related funder(s)Academy of Finland
Funding program(s)Academy Project, AoF
Additional information about fundingThis work was supported by the Academy of Finland underProjects No. 303351, No. 307419, No. 317118, and No.318987, and by the European Research Council (ERC-2013-AdG-340748-CODE). L.L. acknowledges the Aalto Centrefor Quantum Engineering for support. A.J. acknowledgessupport from the Vilho, Yrjö, and Kalle Väisälä Foundation.Computing resources were provided by Triton cluster at AaltoUniversity. We acknowledge grants of computer capacity fromthe Finnish Grid and Cloud Infrastructure (persistent identifierurn:nbn:fi:research-infras-2016072533) ...
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