Effects of antidot shape on the spin wave spectra of two-dimensional Ni80Fe20 antidot lattices

Abstract

We show that the optically induced spin wave spectra of nanoscale Ni80Fe20 (permalloy) antidot lattices can be tuned by changing the antidot shape. The spin wave spectra also show an anisotropy with the variation of the in-plane bias field orientation. Analyses show this is due to various quantized and extended modes, whose nature changes with the antidot shape and bias field orientation as a result of the variation of the internal magnetic field profile. The observed variation and anisotropy in the spin waves with the internal and external parameters are important for their applications in magnonic devices. We gratefully acknowledge the financial supports from Department of Science and Technology, Government of India under the Grant Nos. INT/JP/JST/P-23/09, SR/NM/NS-09/2011(G), and Department of Information Technology, Government of India under Grant No. 1(7)/2010/M&C. We also acknowledge technical helps from Dheeraj Kumar and Bivas Rana during this work. S.B. wants to acknowledge DST (Grant Nos. SR/NM/NS-53/2010 and SR/WOS-A/PS-27/2010) for financial support.