A Bound on Topological Gap from Newton's Laws
arXiv:2407.17603 · doi:10.1103/PhysRevB.110.235133
Abstract
A striking general bound on the energy gap in topological matter was recently discovered in Ref. [Onishi and Fu, Phys. Rev. X {\bf 14}, 011052 (2024)]. A non-trivial indirect derivation builds on the properties of optical conductivity at an arbitrary frequency. We propose a simpler derivation, allowing multiple generalizations, such as a universal bound on a gap in anisotropic systems, systems with multiple charge carrier types, and topological systems with zero Hall conductance. The derivation builds on the observation that the bound equals times the ratio of the force by the external electric field on the charge carriers and their total kinematic momentum in the direction perpendicular to the force.
5 pages
References in corpus (16)
- Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
- Quantum Spin Hall Insulator State in HgTe Quantum Wells
- Observation of the Quantum Spin Hall Effect up to 100 Kelvin in a Monolayer Crystal
- Topological insulators in twisted transition metal dichalcogenide homobilayers
- Signatures of Fractional Quantum Anomalous Hall States in Twisted MoTe2 Bilayer
- Observation of Fractionally Quantized Anomalous Hall Effect
- Ultrastrong coupling of the cyclotron transition of a two-dimensional electron gas to a THz metamaterial
- Quantum anomalous Hall effect from intertwined moiré bands
- Integer and fractional Chern insulators in twisted bilayer MoTe2
- Observation of half-integer thermal Hall conductance
- Quantized Thermal Transport in the Fractional Quantum Hall Effect
- Observed Quantization of Anyonic Heat Flow
- Thirty Years of Composite Fermions and Beyond
- Wavefunctionology: The Special Structure of Certain Fractional Quantum Hall Wavefunctions
- Fractional charge and fractional statistics in the quantum Hall effects
- Fundamental bound on topological gap