Patent ID: 7187576

Claim:
A magnetic tunnel junction (MTJ) configured to be programmed with a plurality of bits, comprising: a soft ferromagnetic layer requiring a low coercivity to magnetize or demagnetize or to change its magnetic orientation, with magnetic anisotropy configured so that the magnetic field of the soft ferromagnetic layer has at least four stable orientations; two hard ferromagnetic layers requiring substantial coercivity to magnetize or demagnetize or to change its magnetic orientation, formed on either side of the soft ferromagnetic layer with magnetic fields oriented in different directions; insulating layers separating the two hard ferromagnetic layers from the soft ferromagnetic layer, each insulating layer having a distinguishable resistance that is dependent on the direction of magnetization of the soft ferromagnetic layer; conductors configured to carry currents to produce magnetic fields to alter the orientation of the magnetic field of the soft ferromagnetic layer; and a sense amplifier configured to sense the resistance of the MTJ.