Department of Physics, Indian Institute of Science, Bangalore 560 012, India.
Phys Rev Lett. 2010 Aug 6;105(6):067206. doi: 10.1103/PhysRevLett.105.067206. Epub 2010 Aug 5.
The stochasticity of domain-wall (DW) motion in magnetic nanowires has been probed by measuring slow fluctuations, or noise, in electrical resistance at small magnetic fields. By controlled injection of DWs into isolated cylindrical nanowires of nickel, we have been able to track the motion of the DWs between the electrical leads by discrete steps in the resistance. Closer inspection of the time dependence of noise reveals a diffusive random walk of the DWs with a universal kinetic exponent. Our experiments outline a method with which electrical resistance is able to detect the kinetic state of the DWs inside the nanowires, which can be useful in DW-based memory designs.
通过测量小磁场下电阻的缓慢波动（即噪声），研究人员探测到了磁纳米线中壁（DW）运动的随机性。通过在镍的孤立圆柱形纳米线中控制 DW 的注入，我们能够通过电阻中的离散步骤跟踪 DW 在电引线之间的运动。对噪声的时间依赖性进行更仔细的检查揭示了 DW 的扩散随机漫步，具有普遍的动力学指数。我们的实验概述了一种方法，即电阻能够检测纳米线内部 DW 的动力学状态，这在基于 DW 的存储器设计中可能很有用。
