Bias dependence of magnetic exchange interactions: application to interlayer exchange coupling in spin valves

Abstract

We study how a bias voltage changes magnetic exchange interactions. We derive a general expression for magnetic exchange interactions for systems coupled to reservoirs under a bias potential, and apply it to spin valves. We find that for metallic systems, the interlayer exchange coupling shows a weak, oscillatory dependence on the bias potential. For tunneling systems, we find a quadratic dependence on the bias potential, and derive an approximate expression for this bias dependence for a toy model. We give general conditions for when the interlayer exchange coupling is a quadratic function of bias potential.

10 pages, 8 figures

References in corpus (7)

• Spin Transfer Torques
• Non-collinear Magnetoelectronics
• Anomalous Bias Dependence of Spin Torque in Magnetic Tunnel Junctions
• Ab initio studies of the spin-transfer torque in tunnel junctions
• Spin-transfer torque in magnetic tunnel junctions: Scattering theory
• Current Induced Order Parameter Dynamics: Microscopic Theory Applied to Co/Cu/Co spin valves
• Implementation of a non-equilibrium Green's function method to calculate spin transfer torque