| 摘要 |
Memory cell structures make use of the extraordinary Hall effect (EHE) for increased data storage capacity. A memory cell has a ferromagnetic structure which includes at least a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer in between the first and the second ferromagnetic layers. The first and the second ferromagnetic layers exhibit perpendicular magnetic anisotropy and have magnetic moments which are set in accordance with one of a plurality of magnetic orientation sets of the ferromagnetic structure, and the ferromagnetic structure exhibits one of a plurality of predetermined extraordinary Hall resistances R<SUB>H </SUB>in accordance with the magnetic orientation set. The extraordinary Hall resistance is exhibited between first and second ends of the ferromagnetic structure across a path which intersects a bias current path between third and fourth ends of the ferromagnetic structure. Thus, the memory cell has at least four memory states including a first memory state associated with a first R<SUB>H </SUB>exhibited when the first and the second ferromagnetic layers are set to first magnetic orientations, a second memory state associated with a second R<SUB>H </SUB>exhibited when the first ferromagnetic layer is set to the first magnetic orientation and the second ferromagnetic layer is set to a second magnetic orientation, a third memory state associated with a third RH exhibited when the first ferromagnetic layer is set to the second magnetic orientation and the second ferromagnetic layer is set to the first magnetic orientation, and a fourth memory state associated with a fourth R<SUB>H </SUB>exhibited when the first and the second ferromagnetic layers are set to the second magnetic orientations. Programmable logic which also makes use of the EHE is also described.
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