AC- and DC-driven noise and I-V characteristics of magnetic nanostructures

Abstract

We study a structure consisting of a ferromagnetic (F) layer coupled to two normal metal (N) leads. The system is driven out of equilibrium by the simultaneous application of external dc and ac voltages across the N/F/N structure. Using the Keldysh diagrammatic approach, and modeling the ferromagnet as a classical spin of size S >> 1, we derive the Langevin equation for the magnetization dynamics and calculate the noise correlator. We find that the noise has an explicit frequency dependence in addition to depending on the characteristics of the ac and dc drive. Further, we calculate the current-voltage characteristics of the structure to O(1/S^2) and find that the nonequilibrium dynamics of the ferromagnetic layer gives rise to corrections to the current that are both linear and nonlinear in voltage.

5 pages, 3 figures, update to published version

References in corpus (8)

• Nonlocal magnetization dynamics in ferromagnetic heterostructures
• Nonequilibrium quantum criticality in open electronic systems
• Functional Keldysh Theory of Spin Torques
• Spin-torque shot noise in magnetic tunnel junctions
• Noise and dissipation in magnetoelectronic nanostructures
• Stochastic dynamics of magnetization in a ferromagnetic nanoparticle out of equilibrium
• Charge pumping and the colored thermal voltage noise in spin valves
• Resistance noise in spin valves

Cited by in corpus (4)

• Strong non-equilibrium effects in spin torque systems
• Mesoscopic Stoner instability in open quantum dots: suppression of Coleman-Weinberg mechanism by electron tunneling
• Unified framework of the microscopic Landau-Lifshitz-Gilbert equation and its application to Skyrmion dynamics
• Dynamic response of a single-electron transistor in the ac Kondo regime