Measurement of Magnetic Field Induced by Spin-Accumulated Electrons in a FeCoB Nanomagnet

The spins, which are accumulated at a boundary of a nanomagnet due to the spin Hall effect, induce a magnetic field, which tilts the nanomagnet magnetization out of its easy axis. Even though this magnetic field is relatively small (about 20 G), it can reverse the magnetization of the nanomagnet if it is modulated in resonance with the magnetization precession and the conditions of the parametric resonance are met. Therefore, such magnetic field can be used to optimize the recording mechanism and to minimize the recording energy for MRAM. A high-precession measurement method of the spin-accumulation-induced magnetic field is developed. The magnetic field is measured in a FeCoB nanomagnet and its properties are studied.