Vortex oscillations in confined Bose-Einstein condensate interacting with one-dimensional optical lattice

We study the Bose-Einstein condensate of atomic Boson gases trapped in a composite potential comprising a harmonic potential and an optical lattice potential. We observed a series of collective excitations that induces localized vortex oscillations with a characteristic wavelength. The oscillations can be observed experimentally when the radial confinement is tight. We present the excitation spectra of the vortex oscillation modes and propose a method to experimentally excite the modes.