Low power scaling using parallel coupling for toggle magnetic random access memory

Toggle-switched magnetic random access memory devices offer wide write margins and robustness against thermally activated switching but are as yet unproven regarding the feasibility of scaling down from present sizes with acceptable write currents. We present a strategy for reducing switching fields by using parallel coupling between the two magnetic free layers, in contrast to the usual antiferromagnetic coupling previously discussed. Combined with the proper free layer magnetic material and offset fields from a carefully imbalanced pinned layer, we present experimental verification of toggling of 130 nm diameter magnetic tunnel junctions at fields of less than 50 Oe. © 2006 American Institute of Physics.