Physics Department, University of Gothenburg, 412 96, Gothenburg, Sweden.
Department of Mathematics, North Carolina State University, Raleigh, North Carolina 27695, USA.
Phys Rev Lett. 2014 Jan 31;112(4):047201. doi: 10.1103/PhysRevLett.112.047201. Epub 2014 Jan 29.
Magnetic dissipative droplets are localized, strongly nonlinear dynamical modes excited in nanocontact spin valves with perpendicular magnetic anisotropy. These modes find potential application in nanoscale structures for magnetic storage and computation, but dissipative droplet studies have so far been limited to extended thin films. Here, numerical and asymptotic analyses are used to demonstrate the existence and properties of novel solitons in confined structures. As a nanowire's width is decreased with a nanocontact of fixed size at its center, the observed modes undergo transitions from a fully localized two-dimensional droplet into a two-dimensional droplet edge mode and then a pulsating one-dimensional droplet. These solitons are interpreted as dissipative versions of classical, conservative solitons, allowing for an analytical description of the modes and the mechanisms of bifurcation. The presented results open up new possibilities for the study of low-dimensional solitons and droplet applications in nanostructures.
磁性耗散液滴是局域的、强非线性动力学模式，在具有垂直各向异性磁的纳米接触自旋阀中被激发。这些模式在纳米结构的磁存储和计算中有潜在的应用，但迄今为止，耗散液滴的研究仅限于扩展薄膜。在这里，数值和渐近分析被用来证明在受限结构中存在新的孤子及其特性。随着纳米线宽度的减小，当纳米线中心的纳米接触尺寸固定时，观察到的模式经历了从完全局域的二维液滴到二维液滴边缘模式，然后是脉动一维液滴的转变。这些孤子被解释为经典的、保守的孤子的耗散版本，允许对模式和分岔机制进行分析描述。所提出的结果为低维孤子和纳米结构中液滴应用的研究开辟了新的可能性。
