Voltage-driven exchange resonance achieving 100\% mechanical efficiency

Abstract

Magnetic resonances driven by current-induced torques are crucial tools to study magnetic materials but are very limited in frequency and mechanical efficiency. We propose an alternative mechanism, voltage-induced torque, to realize high efficiency in generating high-frequency magnetization dynamics. When a ferromagnet-topological insulator-ferromagnet trilayer heterostructure is operated as an adiabatic quantum motor, voltage-induced torque arises from the adiabatic motion of gapped topological electrons on the two interfaces and act oppositely on the two ferromagnetic layers, which can excite the exchange mode where the two ferromagnetic layers precess with a $\pi$-phase difference. The exchange mode resonance, bearing a much higher frequency than the ferromagnetic resonance, is accompanied by topological charge pumping, leading to a sharp peak in electrical admittance at the resonance point. Because the output current is purely adiabatic while dissipative current vanishes identically, the proposed voltage-driven exchange resonance entails a remarkably high mechanical efficiency close to unity, which is impossible in any current-driven systems.

References in corpus (10)

• Topological Field Theory of Time-Reversal Invariant Insulators
• Quantized Anomalous Hall Effect in Magnetic Topological Insulators
• Current-induced spin torque resonance of magnetic insulators
• Magnetic Proximity Effect and Interlayer Exchange Coupling of Ferromagnetic/Topological Insulator/Ferromagnetic Trilayer
• Spin-orbit torque characterization in a nutshell
• Highly Tunable Spin-Orbit Torque and Anisotropic Magnetoresistance in a Topological Insulator Thin Film Attached to Ferromagnetic Layer
• Spin fluctuations in quantized transport of magnetic topological insulators
• Topological electric driving of magnetization dynamics in insulators
• Voltage-driven Magnetization Switching via Dirac Magnetic Anisotropy and Spin--orbit Torque in Topological-insulator-based Magnetic Heterostructures
• Effect of surface hybridization on RKKY coupling in ferromagnet/topological insulator/ferromagnet trilayer system

Cited by in corpus (5)

• Lossless Spin-Orbit Torque in Antiferromagnetic Topological Insulator MnBi${}_2$Te${}_4$
• Emergence of inductance and capacitance from topological electromagnetism
• 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