Beyond Kelvin’s Relation: A Giant Transverse Thomson Response for Efficient Cryogenic Cooling
The Research group of Dr. Subhajit Roychowdhury [Department of Chemistry] developed a new framework for efficient solid-state cooling at cryogenic temperatures, addressing a longstanding challenge in thermoelectric refrigeration. Here, we demonstrate a giant Thomson and transverse Thomson response in the correlated semiconductor FeSb2 below 60 K, enabled by strong phonon-drag enhanced thermoelectric transport. The pronounced temperature dependence of the Seebeck coefficient produces an unusually large longitudinal Thomson coefficient (?800 microV/K), while the simultaneous enhancement of the transverse thermopower under a magnetic field gives rise to a giant transverse Thomson effect (?29 microV/K). These results identify phonon drag as a general and scalable design principle for realizing large Thomson responses. Beyond FeSb2, this framework suggests a pathway to discovering new cryogenic cooling materials by targeting systems with strong phonon–electron coupling, low carrier density, long phonon lifetime, and large thermopower derivatives. More broadly, this work establishes the Thomson effect as a powerful, yet largely unexplored, route for engineering efficient, stable and versatile solid-state cooling platforms for future cryogenic and quantum technologies. For more details, kindly visit https://doi.org/10.1021/jacs.6c02223.
