Hitachi Global Storage Technologies, San Jose, CA 95135, USA.
Nanotechnology. 2010 Jun 11;21(23):235202. doi: 10.1088/0957-4484/21/23/235202. Epub 2010 May 13.
Magnetic field detection with extremely high spatial resolution is crucial to applications in magnetic storage, biosensing, and magnetic imaging. Here, we present the concept of using a spin torque oscillator (STO) to detect magnetic fields by measuring the frequency of the oscillator. This sensor's performance relies predominantly on STO properties such as spectral linewidth and frequency dispersion with magnetic field, rather than signal amplitude as in conventional magnetoresistive sensors, and is shown in measured devices to achieve large signal to noise ratios. Using macrospin simulations, we describe oscillator designs for maximizing performance, making spin torque oscillators an attractive candidate to replace more commonly used sensors in nanoscale magnetic field sensing and future magnetic recording applications.
磁场的超高空间分辨率检测在磁存储、生物传感和磁成像等应用中至关重要。在这里，我们提出了一种利用自旋扭矩振荡器（STO）通过测量振荡器的频率来检测磁场的概念。这种传感器的性能主要依赖于 STO 的特性，如谱线宽度和磁场下的频率色散，而不是传统磁阻传感器中的信号幅度，在测量设备中表现出较大的信噪比。我们使用宏观自旋模拟来描述优化性能的振荡器设计，使自旋扭矩振荡器成为在纳米级磁场传感和未来磁记录应用中替代更常用传感器的有吸引力的候选者。
