Superconductivity Proximate to Non-Abelian Fractional Spin Hall Insulator in Twisted Bilayer MoTe<sub>2</sub>

Oral-In-person

Abstract

Twisted bilayer MoTe2 near two-degree twist has emerged as a platform for exotic correlated topological phases, including ferromagnetism and a non-Abelian fractional spin Hall insulator. Here we reveal the unexpected emergence of an intervalley superconducting phase that intervenes between these two states in the half-filled second moiré bands. Using a continuum model and exact diagonalization, we identify superconductivity through multiple signatures: negative binding energy, a dominant pair-density eigenvalue, finite superfluid stiffness, and pairing symmetry consistent with a time-reversal-symmetric nodal extended s-wave state. Remarkably, our numerical calculation suggests a continuous transition between superconductivity and the non-Abelian fractional spin Hall insulator, in which topology and symmetry evolve simultaneously, supported by an effective field-theory description. Our results establish higher moiré bands as fertile ground for intertwined superconductivity and topological order, and point to experimentally accessible routes for realizing superconductivity in twisted bilayer MoTe2.

Publication: Currently an arXiv preprint, https://doi.org/10.48550/arXiv.2509.23904.

Presenters

  • Cheong Eung Ahn

    • Pohang Univ of Sci & Tech

Authors

  • Cheong Eung Ahn

    • Pohang Univ of Sci & Tech
  • Gyeoul Lee

  • Donghae Seo

    • Pohang Univ of Sci & Tech
  • Youngwook Kim

  • Gil Young Cho

    • Department of Physics, KAIST