2020/07/31 by Maine Christos, Subir Sachdev, Mathias S. Scheurer
Chemistry · Materials Science · Mathematics · Physics and Astronomy · #Bilayer #Bilayer graphene #Chemistry #Condensed matter physics #Dirac fermion #Graphene #Graphene research and applications #Massless particle #Mathematics #Membrane #Physics #Quantum and electron transport phenomena #Quantum mechanics #Superconductivity #Symmetry (geometry) #Symmetry breaking #Topological Materials and Phenomena #Topological insulator #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1073/pnas.2014691117
published as Proceedings of the National Academy of Sciences 117, 29543 (2020) · 26 pages, 3 figures, 15 tables
openalex publication_date 2020/11/09 · arxiv created 2020/12/11 · arxiv updated 2020/12/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
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.