Collective spin excitation in finite size array of patterned magnonic crystals

We explore further details of the collectively excited spin wave mode in finite arrays of elliptically shaped ferromagnetic nanoelements as two-dimensional magnonic crystals by means of micromagnetic simulations. Under a pulsed magnetic driving field, collective spin wave modes were intensively investigated with variation of nanoelement dimensions and interelement separation as structural parameters of the magnonic crystal as well as changing the applied bias magnetic field. Via observing and analyzing the dynamic behavior of collective spin wave modes, we have found that the dynamic behavior strongly depends on the bias magnetic field with a quasi-linear dependency. The quasi-linear dependency of spin wave frequency transition can be achieved to a high sensitivity of the pT/Hz level. By modulating the magnonic crystal lattice structures and the bias magnetic field, the spin wave dynamic behavior is tunable which might be a promising property for a future magnonic crystal application and multifunctional sensors. (C) 2015 Elsevier B.V. All rights reserved.