Location of Repository

Lagrangian formulation of the linear autonomous magnetization dynamics in spin-torque auto-oscillators

By G. Consolo, G. Gubbiotti, L. Giovannini and R. Zivieri


A Lagrangian formalism is used to find steady-state solution of the Landau–Lifshitz–Gilbert–Slonczewski equation corresponding to the linear autonomous dynamics of a magnetic auto-oscillatory system subject to the action of a spin-polarized electric current. In such a system, two concurrent dissipative mechanisms, arising from the positive intrinsic dissipation and the negative current-induced one, take place simultaneously and make the excitation of a steady precessional motion of the magnetization vector conceivable. The proposed formulation leads to the definition of a complex generalized non-Hermitian Eigenvalue problem, both in the case of a macrospin model and in the more general case of an ensemble of magnetic particles interacting each other through magnetostatic and exchange interactions. This method allows to identify the spin-wave normal modes which become unstable in the presence of the two competing dissipative contributions and provides an accurate estimation of the value of the excitation threshold current

Topics: Autonomous dynamics, Auto-oscillators, Complex generalized non-Hermitian\ud Eigenproblem, Lagrange equations, Landau–Lifshitz–Gilbert equation, Micromagnetics, Rayleigh dissipation function, Spin-transfer torque
Year: 2011
DOI identifier: 10.1016/j.amc.2011.02.043
OAI identifier: oai:iris.unife.it:11392/1434310
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • http://hdl.handle.net/11392/14... (external link)
  • Suggested articles

    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.