Sensitive detection of vortex-core resonance using amplitude-modulated magnetic field

• Published in: Scientific reports Vol. 5; no. 1; p. 17922
• Main Authors: Cui, Xiaomin, Hu, Shaojie, Hidegara, Makoto, Yakata, Satoshi, Kimura, Takashi
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 09-12-2015; Nature Publishing Group
• Subjects: 639/766/1130/2798; 639/766/930/12; Circuits; Humanities and Social Sciences; Magnetic fields; multidisciplinary; Science; Spatial discrimination; Thermal stability
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep17922

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.