Detrimental effects of the STO vertical field component in MAMR

As the magnetic recording industry faces challenges to increase areal density while maintaining write-ability, SNR, thermal stability, and reliability, Microwave Assisted Magnetic Recording (MAMR) has been suggested as a technology candidate for future progress [1, 2]. The novel feature of MAMR is the inclusion of a spin-torque oscillator (STO) between the write pole (WP) and trailing shield (TS) of the writer. This STO provides additional energy to assist in switching grains that may not have been able to switch by the writer field alone.