Tracking flat bands via phonon-mediated interband scattering
Abstract
Flat-band (FB) materials have emerged as promising platforms for exploring exotic quantum phases. While numerous candidates have recently been identified through spectroscopic techniques such as angle-resolved photoemission spectroscopy, central challenges remain on how to tune FBs towards the Fermi level and to understand their impact on low-energy excitations probed in electronic transport experiments. Here, we show that, by attributing the temperature dependence of the electrical resistivity at elevated temperatures to electron-phonon interband scattering, one can infer the position of FBs near across diverse material classes. As charge carriers scatter off phonons, interband transitions into FB states lead to distinctive sub- or superlinear resistivity at elevated temperatures, governed by the proximity of the FB to . Our phenomenological model captures these universal transport behaviors observed across several recently studied FB compounds and offers a simple, broadly applicable method for detecting flat bands.
Cite
@article{arxiv.2508.16491,
title = {Tracking flat bands via phonon-mediated interband scattering},
author = {Fabian Garmroudi and Xinlin Yan and Silke Paschen and Sean M. Thomas and Eric D. Bauer and Andrej Pustogow and Priscila F. S. Rosa},
journal= {arXiv preprint arXiv:2508.16491},
year = {2025}
}