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Superconductivity in Twisted Double Bilayer Graphene Stabilized by WSe$_2$

Superconductivity 2025-03-13 v2 Mesoscale and Nanoscale Physics

Abstract

Superconductivity has been previously observed in magic-angle twisted stacks of monolayer graphene but conspicuously not in twisted stacks of bilayer graphene, although both systems host topological flat bands and symmetry-broken states. Here, we report the discovery of superconductivity in twisted double bilayer graphene (TDBG) in proximity to WSe2_2. Samples with twist angles 1.24^\circ and 1.37^\circ superconduct in small pockets of the gate-tuned phase diagram within the valence and conduction band, respectively. Superconductivity emerges from unpolarized states near van Hove singularities and next to regions with broken isospin symmetry, showing the correlation between a high density of states and the emergence of superconductivity in TDBG while revealing a possible role for isospin fluctuations in the pairing.

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Cite

@article{arxiv.2211.16449,
  title  = {Superconductivity in Twisted Double Bilayer Graphene Stabilized by WSe$_2$},
  author = {Ruiheng Su and Manabendra Kuiri and Kenji Watanabe and Takashi Taniguchi and Joshua Folk},
  journal= {arXiv preprint arXiv:2211.16449},
  year   = {2025}
}

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