[14p-501-1~6] 10.3 Spin devices, magnetic memories and storages

▲ [14p-501-3] Relation between Emission Power and Diameter of Spin Torque Oscillator: Micromagnetic Simulation Study

〇Tomohiro Tanaka¹, Atsushi Furuya¹, Yuji Uehara¹, Koichi Shimizu¹, Jun Fujisaki¹, Hirotaka Oshima², Hitoshi Kubota³, Hiroshi Imamura³ (1.Fujitsu Ltd., 2.Fujitsu Labs. Ltd., 3.AIST)

Keywords:spin torque oscillator, micromagnetics

The spin torque oscillators (STOs) are considered as the important devices, because the STOs are expected to be applied in many fields, such as a microwave generator or a magnetic field sensor. Therefore, the development of the STOs with the high emission power and the high Q-factor is in high demand. It has, however, been reported that the emission power of a nano-pillar STO reaches to maximum around 300nm in the diameter. To elucidate this phenomenon, it is important to study the spatial magnetization dynamics of the STOs which show the decrease in the emission power at the large diameter. The STO devices are simulated by the micromagnetics. The results show that the peak of the emission power exists around 300nm in the diameter, and indicate that the magnetization dynamics changes to the incoherent at larger diameter. We will address the mechanism which causes such degradation of the emission power and the physical properties which enhance the emission power.