Antiferromagnetic resonance excited by oscillating electric currents

Abstract

In antiferromagnetic materials the order parameter exhibits resonant modes at frequencies that can be in the terahertz range, making them interesting components for spintronic devices. Here, it is shown that antiferromagnetic resonance can be excited using the inverse spin-Hall effect in a system consisting of an antiferromagnetic insulator coupled to a normal-metal waveguide. The time-dependent interplay between spin-torque, ac spin-accumulation and magnetic degrees of freedom is studied. It is found that the dynamics of the antiferromagnet effects the frequency-dependent conductivity of the normal metal. Further, it is shown that in antiferromagnetic insulators, the resonant excitation by ac spin-currents can be orders of magnitude more efficient than excitation by the current-induced Oersted field.

Version 2: A sign error which I found in the previous version has been corrected. According changes have been made to the text, equations and figures. Apart from that, excitation by spin-torque and Oersted field are now compared under the condition of constant power injection. A new figure and references have been added

References in corpus (8)

• Direct electronic measurement of the spin Hall effect
• Theory of spin Hall magnetoresistance
• Spin pumping and spin-transfer torques in antiferromagnets
• Spin Oscillations in Antiferromagnetic NiO Triggered by Circularly Polarized Light
• Anti-damping spin transfer torque through epitaxial Nickel oxide
• Ultrafast Switching of Antiferromagnets via Spin-transfer Torque
• Current-induced spin torque resonance of magnetic insulators
• Manipulating antiferromagnets with magnetic fields: ratchet motion of multiple domain walls induced by asymmetric field pulses