February 26, 2018
Keio University
A research group led by Visiting Researcher Hong-Yu An (JSPS Postdoctoral Fellow for Foreign Researchers) and Associate Professor Kazuya Ando of the Faculty of Science and Technology, Keio University, in collaboration with Associate Professor Takeo Ohno and others from the Advanced Institute for Materials Research at Tohoku University, has discovered a new principle for operating spintronic devices using insulators. Spintronics is anticipated to be the next generation of electronic technology.
In "spintronics," an electronic technology that utilizes electron spin to make electronic devices faster and more energy-efficient, the key is how to control the magnetization (N/S poles) of magnetic materials (magnets). Recently, methods using spin-orbit interaction within the device to control magnetization have been gaining attention, and using the torque generated by this interaction (spin-orbit torque) enables high-speed, low-power device operation. However, conventional wisdom held that generating spin-orbit torque required passing an electric current through a metal adjacent to the magnetic material. The only way to avoid the energy loss caused by this current was to use topological insulators, which are metallic only on their surface.
Now, this joint research group has demonstrated for the first time in the world that spintronic devices can be driven even using metal oxide insulators, which do not conduct electricity due to the oxidation of the metal. This discovery opens a new path toward realizing low-power devices that minimize the energy loss caused by electric currents in spintronic devices. It is expected that further fundamental research on this newly discovered phenomenon will pave the way for the development of ultra-high-speed, low-power devices and, through them, the realization of an energy-saving society.
This research was published in the American scientific journal "Science Advances" on February 23, 2018 (local time).
Please see below for the full press release.