Magnetization Reversal Process of Tri-Layer Readers for Ultrahigh Density Data Storage

We study the magnetization reversal process of tri-layer readers using micromagnetic simulations. The magnetoresistance response of tri-layer readers has been shown to be distinctive from the conventional spin valve giant magnetoresistance sensors. We look into the challenges for future high storage density when scaling down the read sensor size. The possible sensor reversal process control by engineering the sensor dimensions and material properties has been systematically investigated. We further observe an interesting dependence of magnetization states on the media bit transition length, which could be attributed to the small but finite physical separation between the two coupled ferromagnetic films. The findings in this work are useful for the design of tri-layer sensors for ultrahigh storage density in hard disk drives.