Bandwidth broadening and asymmetric softening of collective spin waves in magnonic crystals

Journal Article · Mon Jun 16 04:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4883878· OSTI ID:22300260

Giovannini, L. ^[1]

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1. Dipartimento di Fisica e Scienze della Terra, CNISM-University of Ferrara, Ferrara, Emilia-Romagna I-44100 (Italy)

We investigate the dependence on the applied field of the frequency/wavevector dispersion relations of collective spin waves in arrays of dots, close to a magnetic transition. In particular, we focus on the low frequency “soft” modes in three different cases: end modes in the transition between two different saturated states in ellipses, fundamental mode in the saturated-to-vortex transition in disks, and gyrotropic mode in the vortex-to-saturated transition in disks. Noteworthy, the spin waves with nonzero Bloch wavevector along the direction of the applied field happen to soften earlier than spin waves with a Bloch wavevector along different directions, and this feature is responsible for an asymmetric broadening of the bandwidth along the different lattice directions. This is particularly useful in magnonic/spin-logic device research, if different binary digits are associated to modes with the same cell function but different propagation directions.

• OSTI ID: 22300260
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 24 Vol. 104; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ASYMMETRY
CRYSTALS
DISPERSION RELATIONS
MAGNONS
SPIN
SPIN WAVES
WAVE PROPAGATION