Thermoelectric enhancement from an asymmetric spectral-conductivity cusp in spin-1 chiral fermions
Abstract
A recent study showed that, in spin-1 chiral fermion systems composed of two linearly dispersing bands and one trivial band, impurity scattering produces an asymmetric cusp in the spectral conductivity. We demonstrate that this asymmetric cusp markedly enhances the electronic thermoelectric response. Using linear-response theory within the self-consistent Born approximation, we find low-temperature enhancements in both the Seebeck coefficient and the electronic figure of merit. Increasing the curvature of the trivial band further strengthens this cusp-induced enhancement, even though the corresponding density of states becomes smoother. To clarify this mechanism, we introduce a minimal cusp model for the spectral conductivity and show that the enhancement is most pronounced when the cusp is sharp and strongly asymmetric, and when the spectral conductivity at the cusp energy is small.
Versions
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BibTeX
@misc{kikuchi2026thermoelectric,
title = {{Thermoelectric enhancement from an asymmetric spectral-conductivity cusp in spin-1 chiral fermions}},
author = {Risako Kikuchi and Junya Endo and Ai Yamakage},
howpublished = {arXiv},
year = {2026},
month = may,
doi = {10.48550/arxiv.2605.13323},
eprint = {2605.13323},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2605.13323},
}
RIS
TY - UNPB
TI - Thermoelectric enhancement from an asymmetric spectral-conductivity cusp in spin-1 chiral fermions
AU - Risako Kikuchi
AU - Junya Endo
AU - Ai Yamakage
PY - 2026
DA - 2026/05/13
PB - arXiv
DO - 10.48550/arxiv.2605.13323
UR - https://arxiv.org/abs/2605.13323
AB - A recent study showed that, in spin-1 chiral fermion systems composed of two linearly dispersing bands and one trivial band, impurity scattering produces an asymmetric cusp in the spectral conductivity. We demonstrate that this asymmetric cusp markedly enhances the electronic thermoelectric response. Using linear-response theory within the self-consistent Born approximation, we find low-temperature enhancements in both the Seebeck coefficient and the electronic figure of merit. Increasing the curvature of the trivial band further strengthens this cusp-induced enhancement, even though the corresponding density of states becomes smoother. To clarify this mechanism, we introduce a minimal cusp model for the spectral conductivity and show that the enhancement is most pronounced when the cusp is sharp and strongly asymmetric, and when the spectral conductivity at the cusp energy is small.
ER -