• 文献标题:   Unconventional superconductivity with preformed pairs in twisted bilayer graphene
  • 文献类型:   Article
  • 作  者:   ISLAM SKF, ZYUZIN AY, ZYUZIN AA
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   2469-9950 EI 2469-9969
  • 通讯作者地址:  
  • 被引频次:   1
  • DOI:   10.1103/PhysRevB.107.L060503
  • 出版年:   2023

▎ 摘  要

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.