title: Narrow Magnonic Waveguides Based on Domain Walls.
abstract: The channeling of spin waves with domain walls in ultrathin ferromagnetic films is demonstrated theoretically and through micromagnetics simulations. It is shown that propagating excitations localized to the wall, which appear in the frequency gap of bulk spin wave modes, can be guided in curved geometries and propagate in close proximity to other channels. For Néel-type walls arising from a Dzyaloshinskii-Moriya interaction, the channeling is strongly nonreciprocal and group velocities can exceed 1  km/s in the long wavelength limit for certain propagation directions. The channeled modes represent an unusual analogy of whispering gallery waves that are one dimensional and nonreciprocal with this interaction. Moreover, a sufficiently strong Dzyaloshinskii-Moriya interaction can create a degeneracy of channeled and propagating modes at a critical wave vector.
authors.affiliation: Institut d'Electronique Fondamentale, UMR CNRS 8622, Université Paris-Sud, 91405 Orsay, France.
authors.forename: Felipe
authors.initials: F
authors.lastname: Garcia-Sanchez
authors.affiliation: SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom.
authors.forename: Pablo
authors.initials: P
authors.lastname: Borys
authors.affiliation: Institut d'Electronique Fondamentale, UMR CNRS 8622, Université Paris-Sud, 91405 Orsay, France.
authors.forename: Rémy
authors.initials: R
authors.lastname: Soucaille
authors.affiliation: Institut d'Electronique Fondamentale, UMR CNRS 8622, Université Paris-Sud, 91405 Orsay, France.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Adam
authors.affiliation: SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Stamps
authors.affiliation: Institut d'Electronique Fondamentale, UMR CNRS 8622, Université Paris-Sud, 91405 Orsay, France.
authors.forename: Joo-Von
authors.initials: JV
authors.lastname: Kim