Abstract
Advent of new-generation materials, with flat topological bands and ultranarrow band gaps (in the order of 1 meV), poses challenges on their precise characterization. We uncover a useful connection between the integrated current noise S(ω) and the topological band gap in dispersionless quantum states, ∫dω[Sxxflat+Syyflat]=Ce2Δ2 (in units ℏ=1), where C is the Chern number, e is electric charge, and Δ is the topological band gap. This relationship may serve as a working principle for experimental probe of topological band gaps in flat band materials. Possible applications include moiré systems, such as twisted bilayer graphene and twisted transition metal dichalcogenides, where a band gap measurement in meV regime presents an experimental challenge.
Original language | English (US) |
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Article number | L041118 |
Journal | Physical Review B |
Volume | 110 |
Issue number | 4 |
DOIs | |
State | Published - Jul 15 2024 |
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics