  The dynamics of a ferromagnetic antivortex wall has been experimentally
studied in a magnetic nanostructure. Two different techniques have been used to
independently measure the eigenfrequency of an antivortex wall such as the
resonance excitation by sinusoidal microwave and the damped resonance
excitation induced by short voltage pulses. Direct observation of antivortex
wall nucleation has been measured in the frequency domain for the first time.
Electrical measurements of the antivortex dynamics in frequency domain reveal
the existence of multi-eigenmodes as well as nonlinear behaviors for large
excitation amplitudes. The time resolved measurements of the antivortex wall
show that the frequency of the damped gyration is similar to that of frequency
domain and coexistence of spin wave excitations.
