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

ORAL

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.

*This work is financially supported by Samsung Science and Technology Foundation under Project Number SSTFBA2401-03, the NRF of Korea (Grants No. RS-2023- 00208291, RS-2024-00410027, 2023M3K5A1094810, RS2023-NR119931, RS-2024-00444725, RS-2023-00256050, IRS-2025-25453111) funded by the Korean Government (MSIT), the Air Force Office of Scientific Research under Award No. FA23862514026, and Institute of Basic Science under project code IBS-R014-D1. This work was performed in part at Aspen Center for Physics, which is supported by National Science Foundation grant PHY-2210452. The work from DGIST was supported by the National Research Foundation of Korea (NRF) (Grant No. RS-2025-00557717, RS-2023-00269616) and the Nano and Material Technology Development Program through the National Research Foundation of Korea (NRF) funded by Ministry of Science and ICT (No. RS2024-00444725). We also acknowledge the partner group program of the Max Planck Society.

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

    • Ulsan National Institute of Science and Technology
  • Donghae Seo

    • Pohang Univ of Sci & Tech
  • Youngwook Kim

    • DGIST
    • Daegu Gyeongbuk Institute of Science and Technology (DGIST)
  • Gil Young Cho

    • KAIST
    • Korea Advanced Institute of Science and Technology