Magnetic Recording Assisted by Spin-Transfer-Torque-Induced Magnetization Reversal and Dynamics

With the requirement of increasing data areal density in hard disk drive (HDD) recording, one of the main applied approaches that effectively reduce recording bit size is to incorporate a spin transfer torque (STT) device in the magnetic writer, either to reverse a magnetic layer in the device in order to guide the magnetic flux of the writer pole more concentrated towards the into and out-of air bearing surface (ABS) directions [1] , or to drive a magnetic layer into large angle oscillations for a sufficiently large radiofrequency (rf) field in the media to realize the assist [2] . Micromagnetic simulations of the magnetic device inside the write gap (WG) between the main writer pole and its magnetic shield with an alternating write gap field, were conducted incorporating STT interactions between the magnetic layers. Modeling results for understanding assist performance optimized by STT device design from these two main approaches are discussed in this talk.