Stebliy M E, Jain S, Kolesnikov A G, Ognev A V, Samardak A S, Davydenko A V, Sukovatitcina E V, Chebotkevich L A, Ding J, Pearson J, Khovaylo V, Novosad V
School of Natural Sciences, Far Eastern Federal University, Vladivostok, 690091, Russia.
Argonne National Laboratory, Materials Science Division, Argonne, 60439, Ilinois, United States.
Sci Rep. 2017 Apr 25;7(1):1127. doi: 10.1038/s41598-017-01222-4.
We explored the dynamic response of a vortex core in a circular nanomagnet by manipulating its dipole-dipole interaction with another vortex core confined locally on top of the nanomagnet. A clear frequency splitting is observed corresponding to the gyrofrequencies of the two vortex cores. The peak positions of the two resonance frequencies can be engineered by controlling the magnitude and direction of the external magnetic field. Both experimental and micromagnetic simulations show that the frequency spectra for the combined system is significantly dependent on the chirality of the circular nanomagnet and is asymmetric with respect to the external bias field. We attribute this result to the strong dynamic dipole-dipole interaction between the two vortex cores, which varies with the distance between them. The possibility of having multiple states in a single nanomagnet with vertical coupling could be of interest for magnetoresistive memories.
我们通过操纵圆形纳米磁体中涡旋核与局部限制在纳米磁体顶部的另一个涡旋核之间的偶极-偶极相互作用，探索了涡旋核的动态响应。观察到与两个涡旋核的回旋频率相对应的明显频率分裂。通过控制外部磁场的大小和方向，可以设计两个共振频率的峰值位置。实验和微磁模拟均表明，组合系统的频谱显著依赖于圆形纳米磁体的手性，并且相对于外部偏置场是不对称的。我们将此结果归因于两个涡旋核之间强烈的动态偶极-偶极相互作用，该相互作用随它们之间的距离而变化。具有垂直耦合的单个纳米磁体中存在多种状态的可能性可能对磁阻存储器具有重要意义。
