Interaction dynamics of a spin-torque oscillator and adjacent nanomagnets: controlling frequency stability and magnetization switching
Mr. Kiwamu Kudo
Date & Time: 15:30 - 16:30, September 28th (Wed), 2016.
Place: 6F Small Seminar Room, Sengen
Abstract:
Over the last decade, spin-torque oscillators (STOs) have been widely studied due to their potential application to future microwave devices, magnetic storages and memories, and computing systems. In this talk, after illustrating the basics of STOs and their applications, we present two topics of our recent simulation studies on the interaction dynamics of an STO and its adjacent nanomagnets. First we show that the oscillation frequency of an STO can be highly stabilized by coupling it with a nanomagnet through the dipolar interaction [1]. The frequency stabilization results from the nanomagnet’s dynamics behaving as a nonlinear resonator for the STO. Second we show that magnetization switching of a nanomagnet can be induced only by using the oscillating magnetic field emitted from an STO without any additional external field [2]. The magnetization switching occurs in a resonant way, which originates from cooperative dynamics with the STO through again the dipolar interaction. This novel resonant magnetization switching enables us to propose a concept of multi-level magnetic memory cells. These findings on the two topics may also provide insight into the mechanism of the so-called microwave-assisted magnetic recording that is one of next-generation magnetic recording technologies. This study was partially supported by Strategic Promotion of Innovative Research and Development from Japan Science and Technology Agency, JST.
[1] K. Kudo, et al., Journal of Applied Physics 116, 163911 (2014).
[2] K. Kudo, et al., Applied Physics Express 8, 103001 (2015).
[1] K. Kudo, et al., Journal of Applied Physics 116, 163911 (2014).
[2] K. Kudo, et al., Applied Physics Express 8, 103001 (2015).