Measurement enhanced determination of BEC phase diagrams
We demonstrate how dispersive atom number measurements during evaporative cooling can be used for enhanced determination of the non linear parameter dependence of the transition to a Bose Einstein condensate (BEC) Our analysis demonstrates that conventional averaging of shot to shot fluctuations introduces systematic errors and reduces precision in comparison with our method. We furthermore compare in situ images from dispersive probing of a BEC with corresponding absorption images in time of flight. This allows for the determination of the transition point in a single experimental realization by applying multiple dispersive measurements. Finally, we explore the continuous probing of several consecutive phase transition crossings using the periodic addition of a focused "dimple" potential.