Perpendicular-anisotropy magnetic tunnel junction switched by spin-Hall-assisted spin-transfer torque. (22nd January 2015)

• Record Type: Journal Article
• Authors: Wang, Zhaohao; Zhao, Weisheng; Deng, Erya; Klein, Jacques-Olivier; Chappert, Claude
• Is Part Of: Journal of physics. Volume 48:Number 6(2015)
• Publication Date: 2015-01-22
• Subjects: magnetic tunnel junction -- perpendicular-anisotropy -- spin-Hall effect -- spin-transfer torque -- electrical model; Physics -- Periodicals; 530
• DOI: 10.1088/0022-3727/48/6/065001
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: We investigate the magnetization switching induced by spin-Hall-assisted spin-transfer torque (STT) in a three-terminal device consisting of a perpendicular-anisotropy magnetic tunnel junction (MTJ) and an β -W strip. Magnetization dynamics in free layer of MTJ is simulated by solving numerically a modified Landau–Lifshitz–Gilbert equation. The influences of spin-Hall write current (density, duration and direction) on the STT switching are evaluated. We find that the switching speed of a STT-MTJ can be significantly improved (reduced to <1 ns) by using a sufficiently large spin-Hall write current density (~25 MA cm −2 ) with an appropriate duration (~0.5 ns). Finally we develop an electrical model of three-terminal MTJ/ β -W device with Verilog-A language and perform transient simulation of switching a 4 T/1MTJ/1 β -W memory cell with Spectre simulator. Simulation results demonstrate that spin-Hall-assisted STT-MTJ has advantages over conventional STT-MTJ in write speed and energy.