Fundamental bound on topological gap

Abstract

We provide a universal tight bound on the energy gap of topological insulators by exploring relationships between topology, quantum geometry, and optical absorption. Applications of our theory to infrared absorption near topological band inversion, magnetic circular dichorism in Chern insulators, and topological gap in moiré materials are demonstrated.

1+10 pages, 1 figure

References in corpus (8)

• Topological Insulators with Inversion Symmetry
• Signatures of Fractional Quantum Anomalous Hall States in Twisted MoTe2 Bilayer
• Integer and fractional Chern insulators in twisted bilayer MoTe2
• Fractional quantum anomalous Hall states in twisted bilayer MoTe${}_2$ and WSe${}_2$
• Dichroic f-sum rule and the orbital magnetization of crystals
• Position-Momentum Duality and Fractional Quantum Hall Effect in Chern Insulators
• Abelian and Non-Abelian Quantum Geometric Tensor
• Momentum-space instantons and maximally localized flat-band topological Hamiltonians

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