title: Spin wave-assisted reduction in switching field of highly coercive iron-platinum magnets.
abstract: Recent rapid progress in spintronic and magnetic storage nanodevices has required nanomagnets to balance competing goals for high coercive field and low switching field. However, a decisive route for highly efficient magnetization switching has not been established yet. Here we propose a novel switching method using a spin wave of magnetic structures twisted in a nanometre scale. We have experimentally demonstrated extremely low field-magnetization switching in a highly coercive FePt by using a spin wave excited in a soft magnetic permalloy (Ni81Fe19), where permalloy is exchange-coupled to FePt through the interface. We can tune the switching field by varying the magnitude and frequency of the radio frequency magnetic field, and a significant decrease in switching field by one order of magnitude is achieved under the optimum conditions. The spin wave-assisted magnetization switching is a promising technique for ultralow-energy magnetization manipulation.
authors.affiliation: Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan. go-sai@imr.tohoku.ac.jp
authors.forename: Takeshi
authors.initials: T
authors.lastname: Seki
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Utsumiya
authors.forename: Yukio
authors.initials: Y
authors.lastname: Nozaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Imamura
authors.forename: Koki
authors.initials: K
authors.lastname: Takanashi