Isaieva K. Stable coherent structures in Bose-condensates of atomic gases

The thesis is devoted to theoretical study of nonlinear structures in Bose-condensates of atomic gases. It is shown that harmonic potential can stablilize vector solitons in Bose-condansate. Time evolution of the condensates which were made from components with spin projections 0,1 and +-1 was compared: in second case supercurrent rapidly decays. For the first case, critical ratio between number of particles in components was found. Conditions of vortex generation in condensate stirred with narrow optical beam were defined. Height of potential barrier between steady states in Bose-condensate was found for different frequencies of wide optical beam rotation. Time of transition between these states was found.