Article

A collaborative team from Tohoku University, Toyohashi University of Technology, Shin-Etsu Chemical Co., Ltd., and MIT has developed a method to create magnetic optical materials that improve data-center communications. Utilizing an ion beam sputtering technique, they fabricated nanoscale magnetic patterns with perpendicular magnetic anisotropy, overcoming previous design limitations related to substrate strain.

The new cerium-substituted yttrium iron garnet (Ce:YIG) films demonstrated strong magnetic properties despite lattice mismatches and formed intricate magnetic domains approximately 219 nm wide. The material showed a Faraday rotation of -1.05°/μm at 1064 nm, outperforming conventional films, and has a low saturation field of 70 mT, enabling energy-efficient magnet usage. These advancements could lead to faster data communications and the development of optical isolators and magneto-optical switches for telecommunications and spintronics applications.