论文标题
来自铁磁通道中耗散交换流的可控涡流
Controllable vortex shedding from dissipative exchange flows in ferromagnetic channels
论文作者
论文摘要
铁磁通道在一个极端注射下进行自旋注射，可维持远程相干纹理，这些远程连贯的质地携带旋转电流称为耗散交换流（DEFS）。在弱注入状态下，DEF携带的自旋电流以衰减代数并延伸到通道的长度，该状态称为自旋超流体。与流体相似，这些结构容易出现表现为涡流抗体对的相。在这里，我们在数字上研究了在具有物理障碍物的磁性纳米线激发的DEFS上脱落的。使用微磁模拟，我们发现层流和涡流脱落的状态是可通过和自旋注入符号和幅度调节的障碍物位置的函数。相对于检测器的极值，涡流 - 抗杀菌对向前转化（VF制度）或向后（VB状态），从而产生了明确定义的光谱特征。当模拟中包括温度，各向异性和弱非本地偶极子场时，在定性上相似的结果。这些结果提供了与DEF相关的明确特征，这些特征可以在具有名义相同边界条件的设备中实验检测到。此外，我们的结果表明，障碍物可以视为DEF控制门，开辟了通过物理缺陷来操纵DEF的途径。
Ferromagnetic channels subject to spin injection at one extremum sustain long-range coherent textures that carry spin currents known as dissipative exchange flows (DEFs). In the weak injection regime, spin currents carried by DEFs decay algebraically and extend through the length of the channel, a regime known as spin superfluidity. Similar to fluids, these structures are prone to phase-slips that manifest as vortex-antivortex pairs. Here, we numerically study vortex shedding from DEFs excited in a magnetic nanowire with a physical obstacle. Using micromagnetic simulations, we find regimes of laminar flow and vortex shedding as a function of obstacle position tunable by the and spin injection sign and magnitude. Vortex-antivortex pairs translate forward (VF regime) or backward (VB regime) with respect to the detector's extremum, resulting in well-defined spectral features. Qualitatively similar results are obtained when temperature, anisotropy, and weak non-local dipole fields are included in the simulations. These results provide clear features associated with DEFs that may be detected experimentally in devices with nominally identical boundary conditions. Furthermore, our results suggest that obstacles can be considered as DEF control gates, opening an avenue to manipulate DEFs via physical defects.
