Work

Evidence for energy-dependent scattering dominating thermoelectricity in heavy fermion systems

Year: 2025

Type: article

Abstract: In the field of thermoelectric materials and devices, improving energy conversion efficiency remains a long-standing challenge. As a promising approach to address this issue, utilizing energy-dependent electron-scattering beyond the ordinary constant relaxation time approximation (CRTA) has been proposed. However, direct experimental evidence for an energy-dependent scattering reflected in the Seebeck coefficient is still lacking. Here, we demonstrate using angle-resolved photoemission spectroscopy that the relaxation time of heavy fermion quasiparticles is highly dependent on the energy near the Fermi level. The observed energy dependence of the relaxation time is due to the coherent Kondo scattering, describing the sign of the Seebeck coefficient reasonably well, which cannot be deduced from CRTA. Our findings provide not only deeper insight into the understanding of thermoelectricity in correlated materials but also future perspectives on possible orbital-selective engineering of thermoelectric materials.

Source: Applied Physics Letters

DOI: 10.1063/5.0291138

Authors: Daiki Goto, Kentaro Kuga, Kiyohisa Tanaka, Tsunehiro Takeuchi, Masaharu Matsunami

Institutions: Toyota Technological Institute, Institute for Molecular Science

Language: English

Topic: Rare-earth and actinide compounds

Subfield: Condensed Matter Physics

Field: Physics and Astronomy

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: green

Funder: Japan Society for the Promotion of Science