• 文献标题:   Superconductivity, correlated insulators, and Wess-Zumino-Witten terms in twisted bilayer graphene
  • 文献类型:   Article
  • 作  者:   CHRISTOS M, SACHDEV S, SCHEURER MS
  • 作者关键词:   twisted bilayer graphene, wesszuminowitten term, strongly correlated system, superconductivity
  • 出版物名称:   PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
  • ISSN:   0027-8424
  • 通讯作者地址:   Harvard Univ
  • 被引频次:   0
  • DOI:   10.1073/pnas.2014691117
  • 出版年:   2020

▎ 摘  要

Recent experiments on twisted bilayer graphene have shown a high-temperature parent state with massless Dirac fermions and broken electronic flavor symmetry; superconductivity and correlated insulators emerge from this parent state at lower temperatures. We propose that the superconducting and correlated insulating orders are connected by Wess-Zumino-Witten terms, so that defects of one order contain quanta of another order and skyrmion fluctuations of the correlated insulator are a "mechanism" for superconductivity. We present a comprehensive listing of plausible low-temperature orders and the parent flavor symmetry-breaking orders. The previously characterized topological nature of the band structure of twisted bilayer graphene plays an important role in this analysis.