General strategy for achieving a large Nernst coefficient
Phys. Rev. B 113, 195111 – Published 14 May, 2026
DOI: https://doi.org/10.1103/37jy-nxd4
Abstract
We propose a general strategy for enhancing the anomalous Nernst coefficient based on the Sommerfeld-Bethe relation. Our formulation expresses the Nernst coefficient in a compact and model-independent form. We show that a large value requires not only a sizable Hall angle but also a pronounced mismatch between the energy dependences (spectral shapes) of the longitudinal and transverse conductivity spectral functions. This perspective provides a transparent explanation for the typically small anomalous Nernst coefficients in simple ferromagnets and yields an explicit optimization criterion. We further present illustrative examples based on simplified spectral-function models designed to highlight how spectral-shape mismatch can strongly enhance the anomalous Nernst coefficient.
