Optimal field-free magnetization switching via spin-orbit torque on the surface of a topological insulator

Ivan P. Miranda; Grzegorz J. Kwiatkowski; Cecilia M. Holmqvist; Carlo M. Canali; Igor S. Lobanov; Valery M. Uzdin; Andrei Manolescu; Pavel F. Bessarab; Sigurður I. Erlingsson

arXiv · 2406.09287

Optimal field-free magnetization switching via spin-orbit torque on the surface of a topological insulator

Ivan P. Miranda·Grzegorz J. Kwiatkowski·Cecilia M. Holmqvist·Carlo M. Canali·Igor S. Lobanov·Valery M. Uzdin·Andrei Manolescu·Pavel F. Bessarab·Sigurður I. Erlingsson

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Abstract

We present an optimal field-free protocol for current-induced switching of a perpendicularly magnetized ferromagnetic insulator nanoelement on the surface of a topological insulator. The time dependence of in-plane components of the surface current, which drives the magnetization reversal via the Dirac spin-orbit torque with minimal Joule heating, is derived analytically as a function of the switching time and material properties. Our analysis identifies that energy-efficient switching is achieved for vanishing damping-like torque. The optimal reversal time that balances switching speed and energy efficiency is determined. When we compare topological insulators to heavy-metal systems, we find similar switching costs for the optimal ratio between the spin-orbit torque coefficients. However, topological insulators offer the advantage of tunable material properties. Finally, we propose a robust and efficient simplified switching protocol using a down-chirped rotating current pulse, tailored to realistic ferromagnetic/topological insulator systems.

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Ivan P. Miranda, Grzegorz J. Kwiatkowski, Cecilia M. Holmqvist, Carlo M. Canali, Igor S. Lobanov, Valery M. Uzdin, Andrei Manolescu, Pavel F. Bessarab, Sigurður I. Erlingsson. 2024-06-13. Optimal field-free magnetization switching via spin-orbit torque on the surface of a topological insulator. https://arxiv.org/abs/2406.09287

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