Fragile topology in line-graph lattices

ORAL

Abstract

The geometric properties of a lattice can have profound consequences on its band spectrum. For example, symmetry constraints and geometric frustration can give rise to topologicially nontrivial and dispersionless bands, respectively. Line-graph lattices are a perfect example of both of these features: their lowest energy bands are perfectly flat, and we have found and proved connections between their geometric properties and the presence or absence of fragile topology in their flat bands [1]. In this talk, I present these connections. This theoretical work will enable experimental studies of fragile topology in several types of line-graph lattices, most naturally suited to superconducting circuits.
[1] C. S. Chiu, D.-S. Ma, Z.-D. Song, B. A. Bernevig, and A. A. Houck. Fragile Topology in Line-Graph Lattices with 2, 3, or 4 Gapped Flat Bands. arXiv: 2010.11953 (2020).

*NSF-MRSEC, the Princeton Materials Science Postdoctoral Fellowship, and the Princeton Center for Complex Materials; MURI; NationalKey R&D Program of China; the National Natural Science Foundation of China; DOE; the Schmidt Fund for Innovative Research; Simons Investigator Grant; the Packard Foundation; NSF-EAGER; ONR; the Gordon and Betty Moore Foundation; and the BSF Israel US foundation.

–

Presenters

  • Christie Chiu

    • Department of Electrical Engineering and Princeton Center for Complex Materials, Princeton University
    • Princeton University
    • Department of Electrical Engineering, Princeton University

Authors

  • Christie Chiu

    • Department of Electrical Engineering and Princeton Center for Complex Materials, Princeton University
    • Princeton University
    • Department of Electrical Engineering, Princeton University

  • Da-Shuai Ma

    • Princeton University
    • Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), Beijing Key Lab of Nanophotonics, and Ultrafine Optoelectronic Systems, and School of Physics,

  • Zhida Song

    • Department of Physics, Princeton University
    • Princeton University
    • Physics, Princeton University

  • Andrei B Bernevig

    • Department of Physics, Princeton University
    • Princeton University
    • Princeto University, Princeton, USA
    • Physics, Princeton University

  • Andrew Houck

    • Princeton University
    • Department of Electrical Engineering, Princeton University