A Compact Model for the Magnetic Tunnel Junction Switched by Thermally Assisted Spin Transfer Torque (STT+TAS)

Thanks to its non-volatility, high write/read speed and easy integration with CMOS process, Magnetic Tunnel Junctions (MTJ) has become a cornerstone of spin electronics such as the Magnetic RAM (MRAM) [1] and Magnetic logic [2-3]. The current research in MTJ nanopillar focus on the high performance (power efficient, high speed and high reliability) switching approaches, as the two high currents used in the conventional methods limit the power and die area of MTJ based circuits. Thermally Assisted Switching [4] was proposed to improve the data stability and reduce the power dissipation but it cannot overcome the miniaturization limits (~65nm). Spin Transfer Toque [5] is one of the most potential approaches to overcome these limits, as there requires only one low current for the switching. However, STT brings new problem: the degradation of thermal stability. Recently, a new approach: Thermally Assisted Spin Transfer Torque (STT+TAS) combining the advantages of both two technologies has been proposed [6], which promises low power, high density and high data stability.