A joint research team, led by Professor Jeong Myung-hwa from Sogang University and Professors Lee Kyung-jin and Kim Gap-jin from the Korea Advanced Institute of Science and Technology (KAIST), has captured, for the first time, the phenomenon of quantum mechanical spin pumping occurring at room temperature.
With charge current, as current flows, electrons collide with atoms inside the material, generating heat and increasing energy consumption. This lowers the efficiency of current generation. To address this, researchers worldwide are conducting studies on creating electronic devices using spin current. The research team focused on the spin pumping phenomenon where spin moves from a ferromagnet to a non-magnetic material due to precession.
Professor Jeong's research team predicted that it would be possible to implement the spin pumping phenomenon quantum mechanically. The team produced iron (Fe)-rhodium (Rh) ferromagnetic thin films and, in collaboration with Professor Kim Gap-jin's team, observed large spin currents utilizing the properties of the thin films. Professor Lee Kyung-jin's team interpreted this using quantum mechanical theory and proved it through additional experiments.
Most quantum mechanical phenomena have only been observed at very low temperatures, but this research is significant as it observed spin pumping at room temperature. Furthermore, since it proposed a method that generates more than ten times the spin current compared to existing classical mechanical methods, it is expected to contribute to the development of next-generation electronic devices.
The research team said: "Unlike previous spintronics research that interpreted magnetization from a classical mechanical perspective, this proves that a quantum mechanical approach is essential in spintronics," adding, "It holds significant implications showing that spintronics technology could serve as a key foundation for quantum technology."