Voltage-driven spin-transfer torque in a magnetic particle

Journal Article · 25 October 2015 · Applied Physics Letters

DOI: https://doi.org/10.1063/1.4934837 · OSTI ID:1469595

Gartland, P. ^[1]; Davidović, D. ^[2]

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1. Georgia Inst. of Technology, Atlanta, GA (United States). School of Physics; School of Physics, Georgia Institute of Technology, 837 State Street, Atlanta, Georgia 30332
2. Georgia Inst. of Technology, Atlanta, GA (United States). School of Physics

In this paper, we discuss a spin-transfer torque device, where the role of the soft ferromagnetic layer is played by a magnetic particle or a magnetic molecule, in weak tunnel contact with two spin polarized leads. We investigate if the magnetization of the particle can be manipulated electronically, in the regime where the critical current for magnetization switching is negligibly weak, which could be due to the reduced particle dimensions. Using master equation simulations to evaluate the effects of spin-orbit anisotropy energy fluctuations on spin-transfer, we obtain reliable reading and writing of the magnetization state of such magnetic particle, and find that the device relies on a critical voltage rather than a critical current. The critical voltage is governed by the spin-orbit energy shifts of discrete levels in the particle. Finally, this finding opens a possibility to significantly reduce the power dissipation involved in spin-transfer torque switching, by using very small magnetic particles or molecules.

• Research Organization: Georgia Inst. of Technology, Atlanta, GA (United States)
• Sponsoring Organization: USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• Grant/Contract Number: FG02-06ER46281
• OSTI ID: 1469595
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 17 Vol. 107; ISSN 0003-6951
• Publisher: American Institute of Physics (AIP)Copyright Statement
• Country of Publication: United States
• Language: English