We study how a bias voltage changes magnetic exchange interactions. We derive a general expression for magnetic exchange interactions for open systems 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 bias dependence must be quadratic.
Citation: Physical Review B (Condensed Matter and Materials Physics)
Pub Type: Journals
Interlayer exchange coupling, spin transfer torque