Spin-wave wells with multiple states created in small magnetic elements

We have observed several localized modes in the spin-wave spectrum of a permalloy microstripe (length 90 mum, width 1 mum, thickness 0.033 mum) magnetized along its width. The mode frequencies increase from 4.5 to 8 GHz with increasing applied field (0-1.1 kOe). These modes are interpreted as multiple spin-wave eigenstates in effective potential wells created by a strongly inhomogeneous internal magnetic field in the stripe near its edges. (C) 2003 American Institute of Physics.