Spin-transfer Antiferromagnetic Resonance

Abstract

Currents can induce spin excitations in antiferromagnets, even when they are insulating. We investigate how spin transfer can cause antiferromagnetic resonance in bilayers and trilayers that consist of one antiferromagnetic insulator and one or two metals. An ac voltage applied to the metal generates a spin Hall current that drives the magnetic moments in the antiferromagnet. We consider excitation of the macrospin mode and of transverse standing-spin-wave modes. By solving the Landau-Lifshitz-Gilbert equation in the antiferromagnetic insulator and the spin-diffusion equation in the normal metal, we derive analytical expressions for the spin-Hall-magnetoresistance and spin-pumping inverse-spin-Hall dc voltages. In bilayers, the two contributions compensate each other and cannot easily be distinguished. We present numerical results for a MnF${}_2|$Pt bilayer. Trilayers facilitate separation of the spin-Hall-magnetoresistance and spin-pumping voltages, thereby revealing more information about the spin excitations. We also compute the decay of the pumped spin current through the antiferromagnetic layer as a function of frequency and the thickness of the antiferromagnetic layer.

arXiv comment10 pages, 5 figures

References in corpus (18)

• Spin Torque Ferromagnetic Resonance Induced by the Spin Hall Effect
• Spin Hall Magnetoresistance Induced by a Non-Equilibrium Proximity Effect
• Theory of spin Hall magnetoresistance
• Spin pumping and spin-transfer torques in antiferromagnets
• Terahertz Antiferromagnetic Spin Hall Nano-Oscillator
• Spin Hall magnetoresistance in antiferromagnet/heavy-metal heterostructures
• Negative spin Hall magnetoresistance of Pt on the bulk easy-plane antiferromagnet NiO
• Tunable sign change of spin Hall magnetoresistance in Pt/NiO/YIG structures
• Inverse Spin Hall Effect in NiFe / Normal Metal Bilayers
• The Intrinsic Magnetization of Antiferromagnetic Textures
• Temperature dependent spin transport properties of Platinum inferred from spin Hall magnetoresistance measurements
• Spin-pumping and Enhanced Gilbert Damping in Thin Magnetic Insulator Films
• Current-induced spin torque resonance of magnetic insulators
• Current-induced spin torque resonance of a magnetic insulator
• Driving and detecting ferromagnetic resonance in insulators with the spin Hall effect
• Spin Pumping and Inverse Spin Hall Voltages from Dynamical Antiferromagnets
• Spin Hall magnetoresistance in antiferromagnet/normal metal bilayers
• Antiferromagnetic resonance excited by oscillating electric currents

Cited by in corpus (7)

• Spin Insulatronics
• Gilbert damping phenomenology for two-sublattice magnets
• Structural sensitivity of the spin Hall magnetoresistance in antiferromagnetic thin films
• Magnon-Mediated Indirect Exciton Condensation through Antiferromagnetic Insulators
• Theory of spin-Hall magnetoresistance in the AC (terahertz) regime
• Electron-magnon spin conversion and magnonic spin pumping in antiferromagnet/heavy metal heterostructure
• Magnon-mediated electric current drag and nonlocal spin-Peltier effect in the ac regime