LMI Seminar: Matter-wave interferometers on the atom chip

Zoom: https://us02web.zoom.us/j/86482660732

Abstract:

Matter-wave interferometry provides an excellent tool for fundamental studies as well as technological applications. In our group, several interferometry experiments have been done with a BEC on an atom chip examining different effects. For example, we studied fluctuations in the nearby environment by an interference of atoms trapped in a magnetic lattice very close (5μm) to a room temperature surface. We realized a new interferometry scheme of self-interfering clocks and showed, in a proof-of-principle experiment, how this could probe the interplay of QM and GR . We also described a rule for “clock complementarity”, which we deduce theoretically and verify experimentally. In the clock interferometer, we have observed phase jumps due to the existence of a geometric phase. Furthermore, we realized Stern-Gerlach interferometry despite several theoretical works which have shown over the years that fundamental barriers exist.

I will give a brief description of the advantages of the atom chip, and will then describe several of the interferometric schemes, and their connection to issues such as environmentally and gravitationally (red-shift) induced decoherence, as well as loss of coherence due to interferometer imprecision (the humpty-dumpty effect). I will conclude with an outlook concerning ideas for possible tests of exotic physics such as quantum gravity, and mention several speculations which we hope to examine in the future.