D2.4 BEC loaded in ring and guide geometries

The development of new laser-beam shaping methods is important in a variety of fields within optics, atomic physics and biophotonics. Spatial light modulators (SLMs) offer a highly versatile method of time-dependent beam shaping, based onimprinting a phase profile onto an incident laser beam which then determines the intensity in the far field, where the atoms are trapped. In recent years, USTAN has demonstrated that engineering a laser beam with an SLM gives precise control of lightintensity patterns and phase patterns at the percentage level [1-4]. Moreover, USTAN has already obtained preliminary results of BECs trapped in these holographic traps, and in this project we will build on these initial results by extending the range ofgeometries that are investigated. In collaboration with UNITS and ABU, more complex trapping configurations will be demonstrated, e.g. several coupled ring traps, Y-junctions and a ring trap coupled to a rectilinear guide, and we will investigate tunnelling between the coupled traps.