Berlin 2012 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 52: Poster II - Magnetic Heusler compounds, Magnetic shape memory alloys, Thin Films, Micro-/Nano-structured magnetic materials, Graphene, Spins in organics, Magnetic imaging, Surface Magnetism, Spin excitations/Torque, Spincaloric transport

MA 52.36: Poster

Freitag, 30. März 2012, 11:00–14:00, Poster A

Interaction of Josephson and magnetic oscillations in Josephson tunnel junctions with a ferromagnetic layer — •Sebastian Mai, Ervand Kandelaki, Anatoly Volkov, and Konstantin Efetov — Theoretische Physik III, Ruhr-Universität Bochum, 44780 Bochum, Deutschland

We studied the dynamics of Josephson junctions with a thin ferromagnetic layer F (SFIFS junctions). In such junctions, the phase difference φ of the superconductors and magnetization M in the F layer are two dynamic parameters coupled to each other. We derived equations describing the dynamics of these two parameters and calculated the modified current-voltage (I-V) characteristics in the presence of a weak magnetic field (Fiske steps). We showed that the magnetic degree of freedom not only changes the form of the Fiske steps but also the overall view of the I-V curve (new peaks related to the magnetic resonance appear). We also calculated the power P absorbed in the system if a microwave radiation with an ac in-plane magnetic field is applied (magnetic resonance). The obtained formula for the power P essentially differs from the one which describes the power absorption in an isolated ferromagnetic film. In particular, this formula describes the peaks related to the excitation of standing plasma waves as well as the peak associated with the magnetic resonance.