title: Direct observation of a propagating spin wave induced by spin-transfer torque.
abstract: Spin torque oscillators with nanoscale electrical contacts are able to produce coherent spin waves in extended magnetic films, and offer an attractive combination of electrical and magnetic field control, broadband operation, fast spin-wave frequency modulation, and the possibility of synchronizing multiple spin-wave injection sites. However, many potential applications rely on propagating (as opposed to localized) spin waves, and direct evidence for propagation has been lacking. Here, we directly observe a propagating spin wave launched from a spin torque oscillator with a nanoscale electrical contact into an extended Permalloy (nickel iron) film through the spin transfer torque effect. The data, obtained by wave-vector-resolved micro-focused Brillouin light scattering, show that spin waves with tunable frequencies can propagate for several micrometres. Micromagnetic simulations provide the theoretical support to quantitatively reproduce the results.
authors.affiliation: CNISM, Unità di Perugia and Dipartimento di Fisica, Università di Perugia, Via A. Pascoli, I-06123 Perugia, Italy. marco.madami@fisica.unipg.it
authors.forename: M
authors.initials: M
authors.lastname: Madami
authors.forename: S
authors.initials: S
authors.lastname: Bonetti
authors.forename: G
authors.initials: G
authors.lastname: Consolo
authors.forename: S
authors.initials: S
authors.lastname: Tacchi
authors.forename: G
authors.initials: G
authors.lastname: Carlotti
authors.forename: G
authors.initials: G
authors.lastname: Gubbiotti
authors.forename: F B
authors.initials: FB
authors.lastname: Mancoff
authors.forename: M A
authors.initials: MA
authors.lastname: Yar
authors.forename: J
authors.initials: J
authors.lastname: Akerman
mesh_terms: D004574:Electromagnetic Fields; D007501:Iron; D008567:Membranes, Artificial; D049329:Nanostructures; D009532:Nickel
chemical_list: D008567:Membranes, Artificial; D009532:Nickel; D007501:Iron