Inter-valley coherent order and fluctuation-mediated superconductivity in rhombohedral trilayer graphene

ORAL

Abstract

Symmetry-broken correlated metals and superconductivity have recently been observed in rhombohedral trilayer graphene. Interestingly, superconductivity always occurs on the cusp of isospin symmetry breaking, indicating that the pairing glue may be provided by order parameter fluctuations. I will argue that the relevant symmetry broken state is inter-valley coherent (IVC), and that IVC fluctuations can lead to unconventional superconductivity which is chiral when the fluctuations are strong. Along the way, I will clarify the role of the inter-valley Hund's coupling in choosing the spin-structure of both the IVC phase and the superconductor, and find a natural explanation of an apparently puzzling feature in the experiments — the occurrence of spin-singlet superconductivity in close proximity of a spin-polarized metal.

*S.C was supported by the U.S. DOE, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division under Contract No. DE-AC02-05-CH11231 through the Scientific Discovery through Advanced Computing (SciDAC) program (KC23DAC Topological and Correlated Matter via Tensor Networks and Quantum Monte Carlo), and the U.S. DOE, Office of Science, Office of Advanced Scientific Computing Research, under the Accelerated Research in Quantum Computing (ARQC) program.M.Z. was supported by the U.S. DOE, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division, under Contract No. DE-AC02-05CH11231, within the van der Waals Heterostructures Program (KCWF16).E.B. was supported by the European Research Council (ERC) under grant HQMAT (Grant Agreement No.~817799), by the Israel-USA Binational Science Foundation (BSF), and by a Research grant from Irving and Cherna Moskowitz.

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Publication: https://arxiv.org/abs/2109.00002

Presenters

  • Shubhayu Chatterjee

    • UC Berkeley
    • University of California, Berkeley

Authors

  • Shubhayu Chatterjee

    • UC Berkeley
    • University of California, Berkeley

  • Taige Wang

    • University of California, Berkeley

  • Erez Berg

    • Weizmann Institute of Science
    • weizmann institute
    • Weizmann Institute

  • Michael P Zaletel

    • University of California, Berkeley
    • University of California at Berkeley