Fabrication of prototype magnetic coupled spin-torque devices for non-volatile logic applications

A Magnetic Coupled Spin-torque Device (MCSTD) is a collective system of three interacting magnetic tunnel junctions (MTJs) that forms a novel magnetic logic gate. The fondamental principle of the MCSTD is the modification of the energy barrier for spin-torque magnetization switching of a central (output) MTJ device arising from changes in the magnetic state of two input MTJ devices. The input MTJs are placed in close proximity of a few tens of nm of the output MTJ such that their magnetic fringing fields are strong enough (> 10 Oersted) to modulate the switching characteristics of the output device. By changing the magnetic states of the two input MTJs, four possible net magnetic fields at the center MTJ can be generated. A single MCSTD thereby enables NAND, NOR and XOR operations. In this paper, the fabrication of a prototype MCSTD device is described and preliminary experiment results are reported. © 2010 Materials Research Society.