A1 Journal article (refereed)
Superfluid weight and Berezinskii-Kosterlitz-Thouless transition temperature of twisted bilayer graphene (2020)

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

JYU authors or editors

Publication details

All authors or editors: Julku, Aleksi; Peltonen, Teemu J.; Liang, Long; Heikkilä, Tero T.; Törmä, Päivi

Journal or series: Physical Review B

ISSN: 2469-9950

eISSN: 2469-9969

Publication year: 2020

Volume: 101

Issue number: 6

Article number: 060505

Publisher: American Physical Society

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1103/PhysRevB.101.060505

Publication open access: Not open

Publication channel open access: 

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/68377

Web address of parallel published publication (pre-print): https://arxiv.org/abs/1906.06313

Abstract

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.

Keywords: nanostructures; graphene; superconductivity

Free keywords: BKT transition; multiband superconductivity; superconducting RF; superconducting fluctuations; superconducting phase transition; superfluid density

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Related projects

Ministry reporting: Yes

Reporting Year: 2020

JUFO rating: 2