Spin Turbulence Made by the Oscillating Magnetic Field in a Spin-1 Spinor Bose-Einstein Condensate

We numerically study spin turbulence made by the oscillating magnetic field in a two-dimensional homogeneous spin-1 spinor Bose-Einstein condensate. We confine ourselves to the case of the ferromagnetic interaction, where the ground state is ferromagnetic. By the oscillating magnetic field along some direction makes the system unstable. At first, the spin density vector revolves in the plane perpendicular to the magnetic field, exciting long-wavelength modes. Secondly, appear some vector components along the magnetic field. Finally, the system becomes spin turbulence. In terms of the energy spectrum of the spin-dependent interaction energy, the peak appears first at low wave number region. Gradually, the peak shifts from low to high wave number region. Eventually, the spectrum exhibits the ?7/3 power law. The ?7/3 power law is confirmed by the scaling analysis using the hydrodynamic equation of the spinor Bose-Einstein condensate.