Current Induced Order Parameter Dynamics: Microscopic Theory Applied to Co/Cu/Co spin valves

Abstract

Transport currents can alter alter order parameter dynamics and change steady states in superconductors, in ferromagnets, and in hybrid systems. In this article we present a scheme for fully microscopic evaluation of order parameter dynamics that is intended for application to nanoscale systems. The approach relies on time-dependent mean-field-theory, on an adiabatic approximation, and on the use of non-equilibrium Greens function (NEGF) theory to calculate the influence of a bias voltage across a system on its steady-state density matrix. We apply this scheme to examine the spin-transfer torques which drive magnetization dynamics in Co/Cu/Co spin-valve structures. Our microscopic torques are peaked near Co/Cu interfaces, in agreement with most previous pictures, but suprisingly act mainly on Co transition metal $d$-orbitals rather than on $s$-orbitals as generally supposed.

9 pages, 5 figures

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Cited by in corpus (38)

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• Spin-orbit torques in Co/Pt(111) and Mn/W(001) magnetic bilayers from first principles
• Ab initio studies of the spin-transfer torque in tunnel junctions
• A knitting algorithm for calculating Green functions in quantum systems
• Current-induced torques due to compensated antiferromagnets
• Spin-transfer torque and spin-polarization in topological-insulator/ferromagnet vertical heterostructures
• Current-Induced Torques in Magnetic Metals: Beyond Spin Transfer
• Laser-induced torques in metallic ferromagnets
• First-principles calculation of spin-orbit torque in a Co/Pt bilayer
• Spin and charge pumping by steady or pulse current-driven magnetic domain wall: A self-consistent multiscale time-dependent-quantum/time-dependent-classical approach
• First-principles spin-transfer torque in CuMnAs$|$GaP$|$CuMnAs junctions
• Implementation of a non-equilibrium Green's function method to calculate spin transfer torque
• Bias dependence of magnetic exchange interactions: application to interlayer exchange coupling in spin valves
• Multi-scale modelling of current-induced switching in magnetic tunnel junctions using ab initio spin transfer torques
• Critical current of spin transfer torque-driven magnetization dynamics in magnetic multilayers
• First-principles quantum transport modeling of spin-transfer and spin-orbit torques in magnetic multilayers
• How to construct the proper gauge-invariant density matrix in steady-state nonequilibrium: Applications to spin-transfer and spin-orbit torques
• Influence of the magnetic material on tunneling magnetoresistance and spin-transfer torque in tunnel junctions: Ab initio studies
• Quantum spin-transfer torque induced nonclassical magnetization dynamics and electron-magnetization entanglement
• Spin-orbit-coupling induced torque in ballistic domain walls: equivalence of charge-pumping and nonequilibrium magnetization formalisms
• Optical spin transfer and spin-orbit torques in thin film ferromagnets
• Thermal spin-transfer torque in magnetic tunnel junctions
• Multiscale approach to spin transport in magnetic multilayers
• Spin-orbit torques and tunable Dzyaloshinskii-Moriya interaction in Co/Cu/Co trilayers
• Determining Perpendicular Magnetic Anisotropy in Fe/MgO/Fe Magnetic Tunnel Junction: A DFT-Based Spin-Orbit Torque Method
• Enhancing the spin transfer torque in magnetic tunnel junctions by ac modulation
• Coupling magneto-elastic Lagrangians to spin transfer torque sources
• Landauer theory of ballistic torkances in non-collinear spin valves
• Spin-torque generation by dc or ac voltages in magnetic layered structures
• First-principles study of spin-transfer torque in Co2MnSi/Al/Co2MnSi spin-valve
• Ballistic vs Diffusive Transport in Current-Induced Magnetization Switching
• Pseudospin Transfer Torques in Semiconductor Electron Bilayers
• Effect of spin diffusion on spin torque in magnetic nanopillars
• Electrical Control of the Exchange Bias Effect at Model Ferromagnet-Altermagnet Junctions
• Non-trivial spatial dependence of the spin torques in L1${}_0$ FePt-based tunnelling junctions
• Adiabatic quantum pumping, magnification effects and quantum size effects of spin-torque in magnetic tunnel junctions
• Reconciling Kubo and Keldysh Approaches to Fermi-Sea-Dependent Nonequilibrium Observables: Application to Spin Hall Current and Spin-Orbit Torque in Spintronics