Reprogrammable magnonic crystals formed by interacting ferromagnetic nanowires

Topp, Jesco; Duerr, Georg; Thurner, Klaus; Grundler, Dirk

doi:10.1351/PAC-CON-11-03-06

Pure Appl. Chem., 2011, Vol. 83, No. 11, pp. 1989-2001

http://dx.doi.org/10.1351/PAC-CON-11-03-06

Published online 2011-07-07

Reprogrammable magnonic crystals formed by interacting ferromagnetic nanowires

Jesco Topp¹, Georg Duerr², Klaus Thurner² and Dirk Grundler²*

¹ Institut für Angewandte Physik und Mikrostrukturforschungszentrum, Universität Hamburg, Junigusstrasse 11, D-20355 Hamburg, Germany
² Lehrstuhl für Physik funktionaler Schichtsysteme, Physik Department E10, Technische Universität München, James-Franck-Strasse 1, D-85747 Garching b. München, Germany

Abstract: Spin-wave (SW) modes are addressed which are confined in thin individual Ni₈₀Fe₂₀ nanowires with widths ranging from 220 to 360 nm. In periodic arrays with an edge-to-edge separation of down to 100 nm, confined modes of neighboring nanowires are found to couple coherently and form allowed minibands and forbidden frequency gaps. This gives rise to a one-dimensional magnonic crystal. We present all-electrical SW spectroscopy data and micromagnetic simulations. We find that the nanowire arrays allow us to reprogram the relevant magnonic band structure via the magnetic history. A forbidden frequency gap of up to about 1 GHz is controlled by an in-plane magnetic field being as small as a few mT.