Lossless Spin-Orbit Torque in Antiferromagnetic Topological Insulator MnBi${}_2$Te${}_4$

Abstract

We formulate and quantify the spin-orbit torque (SOT) in intrinsic antiferromagnetic topological insulator $\mathrm{MnB}{\mathrm{i}}_2\mathrm{T}{\mathrm{e}}_4$ of a few septuple-layer thick, which exhibits conspicuous layer-resolved characteristics. Contrary to known current-induced torques, the SOT in insulating $\mathrm{MnB}{\mathrm{i}}_2\mathrm{T}{\mathrm{e}}_4$ is driven by an electric field (or voltage). We further study the SOT-induced magnetic resonances, where in the tri-septuple-layer case we identify a peculiar exchange mode that is blind to microwaves but can be exclusively driven by the predicted SOT. As an inverse effect of the SOT, topological charge pumping generates an adiabatic current devoid of Joule heating, which occurs concomitantly with the SOT and gives rise to an overall magneto-reactance for $\mathrm{MnB}{\mathrm{i}}_2\mathrm{T}{\mathrm{e}}_4$, enabling a lossless conversion of electric power into magnetic dynamics.

15 pages, 9 figurs

References in corpus (8)

• Topological Field Theory of Time-Reversal Invariant Insulators
• Spin-orbit torques in heavy metal/ferromagnet bilayers with varying strength of interfacial spin-orbit coupling
• Electric control of Dirac quasiparticles by spin-orbit torque in an antiferromagnet
• Intertwined Topological and Magnetic Orders in Atomically Thin Chern Insulator MnBi2Te4
• Current Control of Magnetism in Two-Dimensional Fe3GeTe2
• Non-volatile voltage control of magnetization and magnetic domain walls in magnetostrictive epitaxial thin films
• Voltage-driven exchange resonance achieving 100\% mechanical efficiency
• Quantum interference in a superconductor-${\mathrm{MnBi}}_2{\mathrm{Te}}_4$-superconductor Josephson junction

Cited by in corpus (5)

• Intrinsic Dynamic Generation of Spin Polarization by Time-Varying Electric Field
• Néel Spin-Orbit Torque in Antiferromagnetic Quantum Spin and Anomalous Hall Insulators
• Quantum transport phenomena induced by time-dependent fields
• Spin-orbit torque switching of Néel order in band-inverted antiferromagnetic bilayer MnBi${}_2$Te${}_4$
• Topological Spin-Orbit Torque in Ferrimagnetic Weyl Semimetal