KIP-Veröffentlichungen

This thesis reports on local manipulation of the spin state of a quasi–one–dimensional spinor Bose–Einstein condensate (BEC) of 87Rb atoms. Utilizing the existing laser setup for local control in a novel way enables us to perform local spinor phase rotations on the BEC. Subsequent laser pulses allow for the imprinting of spatial structures, with a resolution of (5.7 ± 0.7)μm. We investigate the temporal evolution of spatially flat initial conditions under di!erent settings for the second–order Zeeman shift. The system evolves locally as predicted by the single–mode approximation (SMA), supporting the use of the local density approximation (LDA). Comparing the oscillations in the relative populations of the side–modes to a simulation of the SMA, we extract e!ective values for the spin-spin interaction (1.5 ± 0.1)Hz and the second–order Zeeman shift. The latter depends linearly on the experimentally programmed value, with a slope of 1.07±0.07. Further analysis of spin dynamics with local spinor phase rotations highlights deviations from the LDA and investigates the conditions for the deterministic preparation of a vortex in the transversal spin in space and time. We show first experiments towards the deterministic preparation of such structures.