CNISM, Unità di Perugia and Dipartimento di Fisica, Università di Perugia, Via A. Pascoli, I-06123 Perugia, Italy.
Nat Nanotechnol. 2011 Aug 28;6(10):635-8. doi: 10.1038/nnano.2011.140.
Spin torque oscillators with nanoscale electrical contacts are able to produce coherent spin waves in extended magnetic films, and offer an attractive combination of electrical and magnetic field control, broadband operation, fast spin-wave frequency modulation, and the possibility of synchronizing multiple spin-wave injection sites. However, many potential applications rely on propagating (as opposed to localized) spin waves, and direct evidence for propagation has been lacking. Here, we directly observe a propagating spin wave launched from a spin torque oscillator with a nanoscale electrical contact into an extended Permalloy (nickel iron) film through the spin transfer torque effect. The data, obtained by wave-vector-resolved micro-focused Brillouin light scattering, show that spin waves with tunable frequencies can propagate for several micrometres. Micromagnetic simulations provide the theoretical support to quantitatively reproduce the results.
具有纳米级电接触的自旋扭矩振荡器能够在扩展的磁性薄膜中产生相干的自旋波，并提供吸引人的电和磁场控制、宽带操作、快速自旋波频率调制以及同步多个自旋波注入点的可能性。然而，许多潜在的应用依赖于传播（相对于局域）的自旋波，并且直接传播的证据一直缺乏。在这里，我们通过自旋转移扭矩效应直接观察到从具有纳米级电接触的自旋扭矩振荡器发射到扩展的坡莫合金（镍铁）薄膜中的传播自旋波。通过波矢分辨微聚焦布里渊光散射获得的数据表明，频率可调的自旋波可以传播几个微米。微磁模拟提供了理论支持，以定量再现结果。
