Integrated magneto-optic Micro traps in atom chips
Atom chips combine cold atom physics with microfabrication techniques to create and manipulate electric, magnetic and optical fields to trap and manipulate atom clouds. In prototype devices, atom chips are already being used to make Bose Einstein condensates and also for applications including clocks, atom interferometry, and quantum information processing.
In experiments to date, atoms are typically initially collected from a warm vapour by a magneto-optical trap (MOT), which holds them as a mm-sized cloud at microKelvin temperatures . The atoms then have to be transferred from the macroscopic MOT cloud to the microscopic traps in the chip. With this loading method, alignment of the traps can be tedious and the atoms are not easily distributed over many micro-traps. We are developing a new approach in which microscopic MOTs integrated into the chip collect small atom clouds in the same location in which they can later be transferred to tighter traps for further manipulation.
We have successfully demonstrated trapped atoms inside silicon microfabricated pyramids on the 4mm scale. The image on the right is a false colour image of approximately 3000 atoms trapped inside one of these pyramids. The MOT is less bright than its reflection as the image of the MOT is positioned above a region of bright scatter inside the pyramid impairing the imaging process.