학술논문

Experimental Demonstration of Efficient Spin–Orbit Torque Switching of an MTJ With Sub-100 ns Pulses
Document Type
Periodical
Source
IEEE Transactions on Magnetics IEEE Trans. Magn. Magnetics, IEEE Transactions on. 53(9):1-7 Sep, 2017
Subject
Fields, Waves and Electromagnetics
Switches
Magnetic tunneling
Electrodes
Torque
Critical current density (superconductivity)
Metals
Magnetic switching
High-speed memory
magnetic tunnel junctions
MRAM scaling
spin Hall effect
spin-orbit torque
Language
ISSN
0018-9464
1941-0069
Abstract
Efficient generation of spin currents from charge currents is of high importance for memory and logic applications of spintronics. In particular, generation of spin currents from charge currents in high spin–orbit coupling metals has the potential to provide a scalable solution for embedded memory. We demonstrate a net reduction in the critical charge current for spin torque-driven magnetization reversal via using spin–orbit mediated spin current generation. We scaled the dimensions of the spin–orbit electrode to 400 nm and the nanomagnet to 270 nm $\times68$ nm in a three-terminal spin–orbit torque, magnetic tunnel junction (SOT-MTJ) geometry. Our estimated effective spin Hall angle is 0.15–0.20 using the ratio of zero-temperature critical current from spin Hall switching and estimated spin current density for switching the magnet. We show bidirectional transient switching using spin–orbit generated spin torque at 100 ns switching pulses reliably followed by transient read operations. We finally compare the static and dynamic response of the SOT-MTJ with transient spin circuit modeling showing the performance of scaled SOT-MTJs to enable nanosecond class non-volatile MTJs.