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Superconductivity in a topological lattice model with purely-repulsive strong interactions

ORAL

Abstract

We present numerical evidence for superconductivity in a microscopic model with purely-repulsive strong interactions. In particular, we propose and investigate a spinful bilayer system of quarter-flux Hofstadter lattices subjected to opposite magnetic fields, equipped with both local Hubbard interactions and inter-layer tunneling. The underlying band structure possesses nearly flat Chern bands related by time-reversal symmetry and possesses $w_2$ fragile topology, much like the flat bands of magic angle bilayer graphene. At integer filling, strong interactions give rise to flavor-polarized insulating states analogous to quantum Hall ferromagnets. Employing the infinite density matrix renormalization group method on a variety of cylinder circumferences, we find striking numerical evidence for $p$-wave superconductivity upon lightly hole-doping a family of these insulators. We conclude by providing a theoretical understanding of the superconducting instability and outlining a potential experimental implementation in an optical lattice.

Presenters

  • Stefan Divic

    University of California, Berkeley

Authors

  • Stefan Divic

    University of California, Berkeley

  • Rahul Sahay

    Harvard University

  • Daniel E Parker

    Harvard University

  • Shubhayu Chatterjee

    UC Berkeley

  • Tomohiro Soejima

    University of California, Berkeley

  • Sajant Anand

    University of California, Berkeley

  • Johannes Hauschild

    University of California, Berkeley

  • Ashvin Vishwanath

    Harvard University

  • Norman Y Yao

    University of California, Berkeley, Harvard University

  • Michael P Zaletel

    University of California, Berkeley, UC Berkeley