Super-Poissonian Shot Noise of Squeezed-Magnon Mediated Spin Transport
Super-Poissonian Shot Noise of Squeezed-Magnon Mediated Spin Transport
复制标题
DOI：
10.1103/physrevlett.116.146601
复制
发表时间：
2016-04-08
影响因子：
8.6
通讯作者：
Belzig, Wolfgang
中科院分区：
文献类型：
--
作者：
Kamra, Akashdeep;Belzig, Wolfgang
被驱离平衡的铁磁体(F)的磁化将纯自旋电流注入到相邻的导体(N)中。这种F-垂直棒-N-双层膜已经成为各种自旋器件的基本构件。当F受到相干微波驱动时，我们计算了穿过F垂直杆N界面的自旋电流的散粒噪声。我们发现，噪声频谱在驱动频率之前是独立于频率的，之后随频率线性增加。低频噪声表明超泊松自旋转移，这是由具有有效自旋的准粒子产生的。(H)在沙洲上=(H)在沙洲(1+三角洲)上。对于典型的铁磁薄膜，类似于1的增量与F本征模的偶极相互作用介导的压缩有关。
The magnetization of a ferromagnet (F) driven out of equilibrium injects pure spin current into an adjacent conductor (N). Such F vertical bar N bilayers have become basic building blocks in a wide variety of spin-based devices. We evaluate the shot noise of the spin current traversing the F vertical bar N interface when F is subjected to a coherent microwave drive. We find that the noise spectrum is frequency independent up to the drive frequency, and increases linearly with frequency thereafter. The low frequency noise indicates super-Poissonian spin transfer, which results from quasiparticles with effective spin. (h) over bar = (h) over bar (1+delta). For typical ferromagnetic thin films, delta similar to 1 is related to the dipolar interaction-mediated squeezing of F eigenmodes.