We propose a method to prepare states of given quantized circulation in annular Bose-Einstein condensates (BEC) confined in a ring trap using the method of phase imprinting without relying on a two-photon angular momentum transfer. The desired phase profile is imprinted on the atomic wave function using a short light pulse with a tailored intensity pattern generated with a spatial light modulator. We demonstrate the realization of "helicoidal" intensity profiles suitable for this purpose. Due to the diffraction limit, the theoretical steplike intensity profile is not achievable in practice. We investigate the effect of imprinting an intensity profile smoothed by a finite optical resolution onto the annular BEC with a numerical simulation of the time-dependent Gross-Pitaevskii equation. This allows us to optimize the intensity pattern for a given target circulation to compensate for the limited resolution.

We prepare a Bose-Einstein Condensate (BEC) in a rotating state, both in a harmonic trap and in a ring trap . Firstly, we form a ”bubble trap” by dressing rubidium atoms in a quadrupole trap with a radiofrequency field. Because of gravity, the atoms are trapped at the bottom of the ”bubble trap”. We then deform the trap by changing the polarization of the dressing radio-frequency, which makes the harmonic trap elliptic. After rotating this trap deformation, we manage to set the gas into rotation in the trap. We observe a vortex lattic, which melts at higher rotation frequencies. As for the ring trap, we shine two parallel blue detuned light sheets to conne the atoms between them. We catch the atoms at the bottom of the bubble between the beams. After shifting the ”bubble” vertically, the ring trap is formed at the intersection of the ”bubble” and the horizontal conning plane. Moreover, we manage to rotate the BEC in this ring trap by using the same method of rotating BEC at the bottom of the ”bubble trap”. This results in a persistent flow of the quantum gas around the annulus.