Phase Engineering and Interferometry with a Bose-Einstein Condensate

J. E. Simsarian and J. Denschlag,
Charles W. Clark, J. Cubizolles, L. Deng, E. W. Hagley, D. L. Feder, K. Helmerson, S. L. Rolston, and W. D. Phillips

We demonstrate quantum phase engineering with two novel techniques that allow us to write and read out the spatial phase distribution of a Bose-Einstein condensate (BEC). A quantum state is designed and produced by optically imprinting a phase pattern onto a BEC of sodium atoms, and matter-wave interferometry with spatially resolved imaging is used to analyze the resultant phase distribution. An appropriate phase imprint creates solitons, the first experimental realization of this nonlinear phenomenon in a BEC. We investigate the subsequent evolution of these excitations both experimentally and theoretically. We also use the interferometer to measure the quantum phase evolution of a BEC that has been released from a magnetic trap.