title: Engineering optical mode ferromagnetic resonance in FeCoB films with ultrathin Ru insertion.
abstract: Ferromagnetic resonance (FMR) in soft magnetic films (SMFs) to a large extent determines the maximum working frequency of magnetic devices. The FMR frequency (fr) in an optical mode is usually much higher than that in the corresponding acoustic mode for exchange coupled ferromagnet/nonmagnet/ferromagnet (FM/NM/FM) trilayers. In this study, we prepared a 50 nm FeCoB film with uniaxial magnetic anisotropy (UMA), showing a high acoustic mode fr of 4.17 GHz. When an ultrathin Ru spacer was inserted in the very middle of the UMA-FeCoB film, the zero-field FMR was abruptly switched from an acoustic mode to an optical one with fr dramatically enhanced from 4.17 GHz to 11.32 GHz. Furthermore, the FMR mode can be readily tuned to optical mode only, acoustic mode only, or double mode by simply varying the applied filed, which provides a flexible way to design multi-band microwave devices.
authors.affiliation: College of Physics, Laboratory of Fiber Materials and Modern Textile, the Growing Base for State Key Laboratory, and Key Laboratory of Photonics Materials and Technology in Universities of Shandong, Qingdao University, Qingdao 266071, China.
authors.forename: Shandong
authors.initials: S
authors.lastname: Li
authors.affiliation: College of Physics, Laboratory of Fiber Materials and Modern Textile, the Growing Base for State Key Laboratory, and Key Laboratory of Photonics Materials and Technology in Universities of Shandong, Qingdao University, Qingdao 266071, China.
authors.forename: Cuiling
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Cardiology, the Affiliated Hospital of Qingdao University, Qingdao 266100, China.
authors.forename: Xian-Ming
authors.initials: XM
authors.lastname: Chu
authors.affiliation: Institute for Quantum Computing, Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, N2L 3G1, Canada.
authors.forename: Guo-Xing
authors.initials: GX
authors.lastname: Miao
authors.affiliation: College of Physics, Laboratory of Fiber Materials and Modern Textile, the Growing Base for State Key Laboratory, and Key Laboratory of Photonics Materials and Technology in Universities of Shandong, Qingdao University, Qingdao 266071, China.|Institute for Quantum Computing, Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, N2L 3G1, Canada.
authors.forename: Qian
authors.initials: Q
authors.lastname: Xue
authors.affiliation: National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China.
authors.forename: Wenqin
authors.initials: W
authors.lastname: Zou
authors.affiliation: Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fujian, 350002, China.
authors.forename: Meimei
authors.initials: M
authors.lastname: Liu
authors.affiliation: College of Physics, Laboratory of Fiber Materials and Modern Textile, the Growing Base for State Key Laboratory, and Key Laboratory of Photonics Materials and Technology in Universities of Shandong, Qingdao University, Qingdao 266071, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Xu
authors.affiliation: College of Physics, Laboratory of Fiber Materials and Modern Textile, the Growing Base for State Key Laboratory, and Key Laboratory of Photonics Materials and Technology in Universities of Shandong, Qingdao University, Qingdao 266071, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.affiliation: School of Physics, Shandong University, Jinan 250100, China.
authors.forename: Youyong
authors.initials: Y
authors.lastname: Dai
authors.affiliation: School of Physics, Shandong University, Jinan 250100, China.
authors.forename: Shishen
authors.initials: S
authors.lastname: Yan
authors.affiliation: School of Physics, Shandong University, Jinan 250100, China.
authors.forename: Shishou
authors.initials: S
authors.lastname: Kang
authors.affiliation: College of Physics, Laboratory of Fiber Materials and Modern Textile, the Growing Base for State Key Laboratory, and Key Laboratory of Photonics Materials and Technology in Universities of Shandong, Qingdao University, Qingdao 266071, China.
authors.forename: Yunze
authors.initials: Y
authors.lastname: Long
authors.affiliation: Department of Physics, School of Science, Harbin Institute of Technology, Harbin, 150001, China.
authors.forename: Yueguang
authors.initials: Y
authors.lastname: Lü