极化电流非对称分布对磁涡旋动力学行为的影响

Influence of asymmetrical spin polarized currents on dynamical behaviors of magnetic vortex

以三个纳米点接触将自旋极化电流通入纳米盘,采用微磁模拟方法,研究了极化电流的大小、方向和间距对磁涡旋动力学行为的影响。结果表明:随电流密度增加磁涡旋均发生了类似旋转回归运动和极性反转。当电流方向为(1,1,1)时,接触点位置非对称分布比接触点位置对称分布时磁涡旋核更易启动,扩大了磁涡旋核做类似旋转回归运动的电流范围,明显减小了极性反转时达到暂态构型的时间,更有利于磁涡旋在纳米振荡器和磁存储方面的应用。当电流方向为(1,1,-1)时,接触点位置非对称分布对磁涡旋的动力学行为影响较小,此时电流方向的非对称分布起主导作用。

We report on micromagnetic simulation results of the dynamical behaviors of magnetic vortex driven by spin polarized currents with three-point-contact geometry.The influence of the magnitudes,directions,and inter-distances of the spin polarized currents on the dynamical behaviors of magnetic vortex was studied.The results indicate that all the magnetic vortex configurations undergo similar gyrotropic motion and polarity switching with the increase of current density.Compared with the symmetrical contact point position,the vortex core can be excited more easily with the asymmetrical contact point position at the current direction of(1,1,1),which expands the current range of similar gyrotropic motion and shortens the time to the transient state of polarity switching.This result makes magnetic vortex more advantageous in the application of spin-torque nano-oscillator and magnetic storage.At the current direction of(1,1,-1)the asymmetrical contact point position has little influence on the dynamical behaviors of magnetic vortex.It is the asymmetrical current direction that plays an important role in the dynamical behaviors of magnetic vortex.