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arXiv · 2212.07202

Non-uniform Superlattice Magnetic Tunnel Junctions

Sabarna Chakraborti·Abhishek Sharma
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Abstract

We propose a new class of non-uniform superlattice magnetic tunnel junctions (Nu-SLTJs) with the Linear, Gaussian, Lorentzian, and P\"oschl-teller width and height based profiles manifesting a sizable enhancement in the TMR($\approx 10^4-10^6\%$) with a significant suppression in the switching bias($\approx$9 folds) owing to the physics of broad-band spin filtering. By exploring the negative differential resistance region in the current-voltage characteristics of the various Nu-SLTJs, we predict the Nu-SLTJs offer the fastest spin transfer torque switching in the order of a few hundred picoseconds. We self-consistently employ the atomistic non-equilibrium Green's function formalism coupled with the Landau-Lifshitz-Gilbert-Slonczewski equation to evaluate the device performance of the various Nu-SLTJs. We also present the design of minimal three-barrier Nu-SLTJs having significant TMR($\approx 10^4\%$) and large spin current for ease of device fabrication. We hope that the class of Nu-SLTJs proposed in this work may lay the bedrock to embark on the exhilarating voyage of exploring various non-uniform superlattices for the next generation of spintronic devices.

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Sabarna Chakraborti, Abhishek Sharma. 2022-12-14. Non-uniform Superlattice Magnetic Tunnel Junctions. https://doi.org/10.1088/1361-6528%2Facb69b

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