title: Sensitive detection of vortex-core resonance using amplitude-modulated magnetic field.
abstract: Understanding and manipulating the dynamic properties of the magnetic vortices stabilized in patterned ferromagnetic structures are of great interest owing to the superior resonant features with the high thermal stability and their flexible tunability. So far, numerous methods for investigating the dynamic properties of the magnetic vortex have been proposed and demonstrated. However, those techniques have some regulations such as spatial resolution, experimental facility and sensitivity. Here, we develop a simple and sensitive method for investigating the vortex-core dynamics by using the electrically separated excitation and detection circuits. We demonstrate that the resonant oscillation of the magnetic vortex induced by the amplitude- modulated alternating-sign magnetic field is efficiently picked up by the lock-in detection with the modulated frequency. By extending this method, we also investigate the size dependence and the influence of the magneto-static interaction in the resonant property of the magnetic vortex.
authors.affiliation: Graduate School of Information Science and Electrical Engineering, Kyushu University, 744 Motooka, Fukuoka, 819-0395, Japan.
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Cui
authors.affiliation: Graduate School of Information Science and Electrical Engineering, Kyushu University, 744 Motooka, Fukuoka, 819-0395, Japan.
authors.forename: Shaojie
authors.initials: S
authors.lastname: Hu
authors.affiliation: Department of Physics, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Hidegara
authors.affiliation: Department of Information Electronics, Fukuoka Institute of Technology, 3-30-1 Wajiro-higashi, Higashi-ku, Fukuoka, 811-0295 Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yakata
authors.affiliation: Department of Physics, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581, Japan.|Research Center for Quantum Nano-Spin Sciences, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581, Japan.|CREST, Japan Science and Technology Agency, Sanbancho, Tokyo 102-0075, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kimura