In the 1850s, Lord Kelvin predicted the existence of a thermoelectric cooling effect inside a whole material (the Thomson effect) according to thermodynamics¹, in addition to the Peltier effect that enables cooling at the junction between dissimilar materials. However, the Thomson effect is usually negligible (ΔT/T < 2%) in conventional thermoelectric materials because the entropy change in charge carriers is fairly small², leading to the guiding principles for advancing thermoelectric cooling to be based on the framework of the Peltier effect and that the figure of merit ZT should be maximized to optimize performance. Here, we demonstrate a Thomson-effect-enhanced thermoelectric cooler using a large Thomson coefficient (τ) induced by the direct manipulation of charge entropy through an electronic phase transition in YbInCu₄. The devices achieve a steady temperature span (ΔT) of >5 K from T = 38 K. Our findings suggest not only another approach to advance thermoelectric coolers in addition to improving ZT but also technologically opens opportunities for solid-state cryogenic cooling applications.

在 1850 年代，开尔文勋爵根据热力学¹ 预测了整个材料内部存在热电冷却效应（汤姆逊效应），此外还有能够在不同材料之间的连接处进行冷却的珀尔贴效应。然而，在常规热电材料中，汤姆逊效应通常可以忽略不计 （ΔT/T < 2%），因为载流子的熵变相当小²，导致推进热电冷却的指导原则基于珀尔帖效应的框架，并且品质因数 ZT应最大化以优化性能。在这里，我们展示了一个使用大汤姆逊系数 （τ） 的汤姆逊效应增强热电冷却器，该系数是通过 YbInCu₄ 中的电子相变直接操纵电荷熵引起的。这些器件在 T = 38 K 时实现了 >5 K 的稳定温度范围 （ΔT）。我们的研究结果不仅提出了除了改进 ZT 之外推进热电冷却器的另一种方法，而且还在技术上为固态低温冷却应用开辟了机会。