Feasibility of an active-read approach for spin-torque switched magnetic tunnel junctions in a random access memory

The circuit element behavior during an active read-out approach is analyzed for the detection of the bit-state of a spin-transfer-torque (STT) switchable magnetic tunnel junction (MTJ) as a storage bit in a random access memory. Fundamentally, such read-out schemes detect the presence or absence of a hysteresis in the current-voltage characteristic of the MTJ depending on its magnetic configuration and the bias direction. A quantitative assessment is given in terms of the range of threshold distribution to be expected, and the read-out time one can achieve as it depends on various device parameters. The quantitative results given are based on an approximate macrospin model for the STT-switched MTJ. © 2013 AIP Publishing LLC.