Unraveling Topological Crystalline Materials with Spin-Resolved Topology in Insulators and Dual Charge-Resolved Topology in Superconductors

ORAL

Abstract

3D topological crystalline insulators (TCIs) are abundant in nature, but exhibit bulk responses, classification groups, surface anomalies, and fermion-doubling exceptions that are poorly understood compared to those of standard topological insulators. It was recently shown that the spin-resolved topology of the projected U(1)-spin spectrum can be used to overcome these issues in nonmagnetic TCIs, specfically revealing the existence of bulk partial axion angles and anomalous surface half quantum spin Hall states. Building on this progress, we here introduce a ``dual'' framework of U(1)-charge resolved topology in topological (crystalline) superconductors (SCs). Combining spin- and charge-resolved topology with a refined notion of second-quantized-embedded SC symmetry groups, we formulate complementary real- and momentum-space invariants for nodeless SCs with arbitrary numbers of spin, orbital, and sublattice degrees of freedom, and arbitrarily complicated pairing terms beyond the weak-coupling regime. Our study reveals new hierarchies of and relationships between normal-state TCIs and topological crystalline SCs, whose surface anomalies expand upon and recontextualize the celebrated Fu-Kane proximity effect.

*ERC-StG-101117835-TopoRosetta, ANR-20-IDEES-0002, AFOSR FA9550-21-1-0131, NSF DMR-1945058, DOE DE-SC0022168, NSF DMR-2114825

Presenters

  • Benjamin J Wieder

    • Université Paris-Saclay

Authors

  • Benjamin J Wieder

    • Université Paris-Saclay
  • Siddhartha Sarkar

    • University of Michigan
    • Max Planck Institute for Physics of Complex Systems
  • Kuan-Sen Lin

    • Rice University
  • Giandomenico Palumbo

    • Dublin Institute for Advanced Studies
  • Yoonseok Hwang

    • University of Illinois Urbana-Champaign
  • Eli Gerber

    • Universite Paris-Saclay
  • Senthil Todadri

    • Massachusetts Institute of Technology
  • Gregory A Fiete

    • Northeastern University
  • Barry Bradlyn

    • University of Illinois at Urbana-Champaign
    • University of Illinois Urbana-Champaign