Programmable spintronics logic device based on a magnetic tunnel junction element

A programmable spintronics logic device was designed and fabricated based on a single pinned magnetic tunnel junction (MTJ) element. In this work, a current input line C passing through the MTJ element itself was introduced. Two separated input current lines (A and B) could switch the magnetization of the pinned layer under the heat assistance from line C. Full logic functions (AND, OR, NAND, NOR, XOR, and XNOR) can be realized based on a normal pinned and a synthetic pinned MTJ element. A Wheatstone bridge was engineered to read this single MTJ element logic device. MTJ elements with 1μm2 and normal pinned structure: (Ta30Å∕NiFe40Å∕MnIr35Å∕CoFe30Å∕(Al7Å)+oxidation∕CoFe30Å∕NiFe40Å∕Ta200Å), have low resistance of 6.3Ω and high resistance of 7.2Ω, which gives the magnetoresistive (MR) ratio of 14%. Approximately a 3-mV output difference is obtained between logical 1 and 0.