Current induced spin transfer noise in CPP-GMR based Heusler alloy

摘要

Spin transfer torque (STT) induced magnetic noise is an important role in the current perpendicular to the plane (CPP) read heads since it generates the instability. Thus, this work examines STT noise caused by the sense current in the CPP giant magnetoresistance (GMR) read heads based on the Heusler alloy. The magnetization dynamic due to the sense current is computed by LLGS equation. The power spectral density of magnetization is considered to investigate the noise power. The results show that STT causes the energy pumping into a system affecting to the magnetization dynamic. Also, the maximum noise power occurs when the current reaches a critical value. Hence, STT noise is the main point to develop the future hard disk drive technology since it affects the stability of CPP-GMR heads.