Field-Free Spin-Orbit Torque Switching in Janus Chromium Dichalcogenides.

Vojáček, Libor; Medina Dueñas, Joaquín; Li, Jing; Ibrahim, Fatima; Manchon, Aurélien; Roche, Stephan; Chshiev, Mairbek; García, José H · Nano Lett · 2024

basic_science · Level V

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Abstract

We predict a very large spin-orbit torque (SOT) capability of magnetic chromium-based transition-metal dichalcogenide (TMD) monolayers in their Janus forms CrXTe, with X = S, Se. The structural inversion symmetry breaking, inherent to Janus structures is responsible for a large SOT response generated by giant Rashba splitting, equivalent to that obtained by applying a transverse electric field of ∼100 V nm<sup>-1</sup> in non-Janus CrTe<sub>2</sub>, completely out of experimental reach. By performing transport simulations on carefully derived Wannier tight-binding models, Janus systems are found to exhibit an SOT performance comparable to the most efficient two-dimensional materials, while additionally allowing for field-free perpendicular magnetization switching, due to their reduced in-plane symmetry. Altogether, our findings evidence that magnetic Janus TMDs stand as suitable candidates for ultimate SOT-MRAM devices in an ultracompact self-induced SOT scheme.