Spin based electronic device

A thin film spin polarized electron current device comprising:

• a first conductive layer separated from a separate second conductive layer;
• a first thin film ferromagnetic structure characterized by a first coercivity, and electrically coupled to said first conductive layer;
• wherein said first thin film ferromagnetic structure is configured to have a fixed magnetization state;
• a second thin film ferromagnetic structure characterized by a second coercivity substantially smaller than said first coercivity, and electrically coupled to said second conductive layer;
• wherein only said second thin film ferromagnetic structure has a changeable magnetization state responsive to an external magnetic field;
• a base layer between said first thin film ferromagnetic structure and said second thin film ferromagnetic structure, which base layer includes a material having equilibrium energy levels for electron spins which are substantially the same;
• wherein said base layer includes a first low transmission barrier at an interface to said first thin film ferromagnetic structure, and a second low transmission barrier at an interface to said second thin film ferromagnetic structure;
• wherein a spin polarized current flows in part in a path perpendicular to a magnetization plane of said second thin film ferromagnetic structure and said first thin film ferromagnetic structure;
• further wherein a value of said spin polarized current can be measured to determine a relationship between said changeable magnetization state and said second non-changeable magnetization state.

A thin film electron spin-based sensing device comprising:

• i) a first thin film ferromagnetic layer with a changeable magnetization state comprising permalloy and/or cobalt;
• ii) a second thin film ferromagnetic layer with a non-changeable magnetization state also comprising permalloy and/or cobalt;
• iii) at least one third thin film layer situated between said first thin film ferromagnetic layer and said second thin film ferromagnetic layer, said at least one third thin film layer comprising a material with equilibrium levels which are substantially equal for two different electron spins present in a spin polarized current, said at least one third thin film layer including a low transmission barrier interface to said first thin film ferromagnetic layer and/or said second thin film ferromagnetic layer;
• wherein said spin polarized current flows at least in part perpendicular to first and second thin film ferromagnetic layers and varies in accordance with a relationship between said changeable magnetization state and said non-changeable magnetization state.