Josephson Junctions for a BEC in a Toroidal Trap

The Josephson Effect is one of the most important consequences of superconductivity and superfluidity. It also plays a crucial role in many technological innovations, including the SQUID. Previous experimental work on creating Josephson Junctions and studying the Josephson Effect with a BEC has mostly relied on somewhat inflexible methods to create the junctions, limiting possible geometries. Here we report our work towards creating arbitrary Josephson Junction arrays based on our ``painted potential'' method for manipulating BECs. In the previous work, arbitrary potentials for a BEC, including a toroidal trap, were created by using the time averaged optical dipole potential of a 2D scanning laser beam. To implement tunneling junctions, a high resolution long distance objective was installed, allowing painting of arbitrary potentials with a resolution of 1.5 micron. One particularly interesting Josephson Junction geometry is that of a BEC in a toroidal trap with tunneling junctions, which would be analogous to a SQUID. This configuration can be used to sense rotation and create a Schr\"{o}dinger cat state of different flow states. Towards this goal, we painted two symmetric Josephson Junctions for a BEC in a toroidal trap and studied Josephson effects in this set up. In this poster we will report progress on this experiment.