• 文献标题:   Isospin order in superconducting magic-angle twisted trilayer graphene
  • 文献类型:   Article
  • 作  者:   LIU XX, ZHANG NJ, WATANABE K, TANIGUCHI T, LI JIA
  • 作者关键词:  
  • 出版物名称:   NATURE PHYSICS
  • ISSN:   1745-2473 EI 1745-2481
  • 通讯作者地址:  
  • 被引频次:   13
  • DOI:   10.1038/s41567-022-01515-0 EA FEB 2022
  • 出版年:   2022

▎ 摘  要

The discovery of magic-angle twisted trilayer graphene unlocks various properties of the superconducting phase, such as violation of the Pauli limit and re-entrant superconductivity at large in-plane magnetic fields(1-3). Here we integrate magic-angle twisted trilayer graphene into a double-layer structure to study the superconducting phase. Using proximity screening from the adjacent metallic layer, we examine the stability of superconductivity and demonstrate that Coulomb repulsion competes with the mechanism underlying Cooper pairing. Furthermore, we use a combination of transport and thermodynamic measurements to probe the ground-state order(4-6), which points towards a spin-polarized and valley-unpolarized configuration at half moire filling and for the Fermi surface at doping levels close to that point. Our findings provide important constraints for theoretical models aiming to understand the nature of superconductivity. A possible scenario is that electron-phonon coupling stabilizes a superconducting phase with a spin-triplet, valley-singlet order parameter(7-13).