Unconventional superconductivity with preformed pairs in twisted bilayer graphene

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Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2023-02-01
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Language
en
Pages
6
1-6
Series
Physical Review B, Volume 107, issue 6
Abstract
We present a theory of superconductivity in magic-angle twisted bilayer graphene and analyze the superconducting phase diagram in the presence of the magnetic field. Namely, we consider a model of a granular array hosting localized states, which are hybridized via the delocalized fermions in the intergrain regions. We study a strong-coupling situation when the interactions lead to an incoherent state with preformed Cooper pairs inside the grains. The Andreev scattering among different grains manifests itself through the global phase-coherent superconducting state at lower temperatures. We demonstrate that a new phase transition between the preformed Cooper pairing state and the Larkin-Ovchinnikov-Fulde-Ferrell state might be induced by the spin pair-breaking effect of in-plane magnetic field. The upper critical magnetic field is shown to be enhanced in the strong-coupling case.
Description
Funding Information: This work is supported by Academy of Finland Grant No. 308339. A.A.Z. also acknowledges the Center of Excellence in Quantum Technology Finland. The authors acknowledge Jose Lado for useful comments. Publisher Copyright: © 2023 American Physical Society.
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Citation
Islam, S F, Zyuzin, A Y & Zyuzin, A A 2023, ' Unconventional superconductivity with preformed pairs in twisted bilayer graphene ', Physical Review B, vol. 107, no. 6, L060503, pp. 1-6 . https://doi.org/10.1103/PhysRevB.107.L060503