Patent ID: 8619467

Claim:
A multi-layer structure, comprising: a plurality of multi-layer periods, each multi-layer period including: a first structure having a plurality of magnetic layers separated by intervening non-magnetic layers, the plurality of magnetic layers including outer magnetic layers, the first structure being characterized by anti-ferromagnetic coupling between adjacent ones of the magnetic layers, and having an overall magnetization orientation that is antiparallel with magnetization orientations of the outer magnetic layers; and a second structure adjacent and separated from the first structure by an intervening non-magnetic layer, the second structure comprising one or more magnetic layers; wherein each second structure has an active magnetic interface with the outer magnetic layer of one or more adjacent first structures, the intervening non-magnetic layer having a thickness such that the active magnetic interface is characterized by ferromagnetic coupling, and wherein when relative magnetization orientations across each active magnetic interface are reversed, a resistance of the multi-layer structure changes.