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Fragile topology in line-graph lattices

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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).

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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