A Dual Free Layer Sensor With Side Shields

We use a hybrid finite element code to explore the design space of a dual free layer (or trilayer) magnetic sensor to understand the effect of the stripe height (SH) to track width (TW) ratio on the bias point, as well as the noise. Transfer curves and noise properties are found to be strongly sensitive to the SH/TW ratio compared to a standard single free layer sensor. Side shields can change the eigenmodes of the coupled system and modify the noise cancellation.