Spin waves in circular soft magnetic dots at the crossover between vortex and single domain state

Farkhad G. Aliev,1,* Juan F. Sierra,1 Ahmad A. Awad,1 Gleb N. Kakazei,2,† Dong-Soo Han,3 Sang-Koog Kim,3 Vitali Metlushko,4 Bojan Ilic,5 and Konstantin Y. Guslienko3,6 1Departamento de Fisica de la Materia Condensada, CIII, Instituto “Nicolas Cabrera” de Ciencia de Materiales, Universidad Autonoma de Madrid, 28049 Madrid, Spain 2Departamento de Física da Faculdade de Ciências, IFIMUP and IN-Institute of Nanoscience and Nanotechnology, Universidade do Porto, 4169-007 Porto, Portugal 3Research Center for Spin Dynamics and Spin-Wave Devices, Seoul National University, Seoul, 1510744 South Korea 4Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, Illinois, 60607 USA 5Cornell Nanofabrication Facility, Cornell University, Ithaca, New York, 14853 USA 6Departamento de Fisica de Materiales, Universidad del Pais Vasco, 20018 Donostia-San Sebastian, Spain Received 21 April 2009; published 28 May 2009