Nanosecond-timescale low error switching of in-plane magnetic tunnel junctions through dynamic Oersted-field assisted spin-Hall effect

• Published in: arXiv.org
• Main Authors: Aradhya, Sriharsha V, Rowlands, Graham E, Oh, Junseok, Ralph, Daniel C, Buhrman, Robert A
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 21.06.2016
• Subjects: Computer memory; Computer simulation; Current pulses; Electromagnetism; Error analysis; Hall effect; Physics - Materials Science; Physics - Mesoscale and Nanoscale Physics; Spin dynamics; Switching; Torque; Tunnel junctions; Variations
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1605.02104

We investigate fast-pulse switching of in-plane-magnetized magnetic tunnel junctions (MTJs) within 3-terminal devices in which spin-transfer torque is applied to the MTJ by the giant spin Hall effect. We measure reliable switching, with write error rates down to \(10^{-5}\), using current pulses as short as just 2 ns in duration. This represents the fastest reliable switching reported to date for any spin-torque-driven magnetic memory geometry, and corresponds to a characteristic time scale that is significantly shorter than predicted possible within a macrospin model for in-plane MTJs subject to thermal fluctuations at room temperature. Using micromagnetic simulations, we show that in the 3-terminal spin-Hall devices the Oersted magnetic field generated by the pulse current strongly modifies the magnetic dynamics excited by the spin-Hall torque, enabling this unanticipated performance improvement. Our results suggest that in-plane MTJs controlled by Oersted-field-assisted spin-Hall torque are a promising candidate for both cache memory applications requiring high speed and for cryogenic memories requiring low write energies.