2022/10/01 by Alexander Kruchkov, Kruchkov, Alexander
Physics and Astronomy · #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Quantum and electron transport phenomena #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con)
paper · pdf · doi:10.48550/arxiv.2210.00351
openalex publication_date 2022/10/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Flat electronic bands are counterintuitive: with the electron velocity vanishing, our conventional notions of quasiparticle transport are no longer valid. We here study the quantum transport in the generalized families of perfectly flat bands [PRB 105, L241102 (2022)], and find that while the conventional contributions indeed vanish, the quantum-geometric contribution gives rise to the enhanced electronic transport. This contribution is connected to the Wannier orbital quantization in the perfectly flat bands, and is present only for geometrically-nontrivial bands (for example, flat Chern bands). We find similar expressions for thermal conductance, thermoelectric response, and superfluid weight in the flat bands. In particular, we report the anomalous thermopower associated with flat topological bands reaching values as large as (kB)/(e)ln 2≈60 μV/k, the quantum unit of thermopower, not expected in conventional dispersive bands.