Spin caloritronics: history and future prospects of experiments

Since the beginning of the 21st century, novel energy conversion and control principles utilizing the spin degree of freedom have been discovered in the field of spin caloritronics, which integrates spintronics with thermal transport and thermoelectric properties. In this article, we review the history of development of spin caloritronics and experimental studies on various transport phenomena caused by heat-charge-spin interactions. We then discuss future prospects in spin caloritronics from the viewpoints of measurement techniques, physics, materials science, and engineering applications. Spin caloritronics is now at a turning point, transitioning from fundamental condensed matter physics to materials science, and further development is anticipated in both fundamental and applied research.