Critical current density of a spin-torque oscillator with an in-plane magnetized free layer and an out-of-plane magnetized polarizer

R Matsumoto,H Imamura

doi:10.1063/1.4972263

R Matsumoto, H Imamura

Open Access

https://doi.org/10.1063/1.4972263

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Abstract

Spin-torque induced magnetization dynamics in a spin-torque oscillator with an in-plane (IP) magnetized free layer and an out-of-plane (OP) magnetized polarizer under IP shape-anisotropy field (Hk) and applied IP magnetic field (Ha) was theoretically studied based on the macrospin model. The rigorous analytical expression of the critical current density (Jc1) for the OP precession was obtained. The obtained expression successfully reproduces the experimentally obtained Ha-dependence of Jc1 reported in [D. Houssameddine et al., Nat. Mater. 6, 447 (2007)].

Highlights

Critical current density of a spin-torque oscillator with an in-plane magnetized free layer and an out-of-plane magnetized polarizer
We theoretically analyzed spin-torque induced magnetization dynamics in the spin-torque oscillator (STO) with an IP magnetized free layer and an OP magnetized polarizer in the presence of Hk and Ha based on the macrospin model
The lateral size of the nano-pillar is assumed to be so small that the magnetization dynamics can be described by the macrospin model

Summary

Introduction

Critical current density of a spin-torque oscillator with an in-plane magnetized free layer and an out-of-plane magnetized polarizer. When the current density (J) of the applied dc current exceeds the critical value (Jc1), the 360◦ in-plane precession of the free layer magnetization, so-called OP precession, is induced by the spin torque. We theoretically analyzed spin-torque induced magnetization dynamics in the STO with an IP magnetized free layer and an OP magnetized polarizer in the presence of Hk and Ha based on the macrospin model.

Results

Conclusion