Title: Entangled matter waves for sub-shot-noise interferometry Speaker: Carsten Klempt Leibniz Universität, Hannover Time: Friday, November 18th, 15.15 to 16.00 Place: 1525-323 Abstract: Matter wave optics with ultracold samples has reached the point where nonclassical states can be prepared and their fascinating properties can be explored. In optics, parametric down conversion is routinely used to generate light with squeezed observables as well as highly entangled photon pairs. The applications of these nonclassical states range from fundamental tests of quantum mechanics to improved interferometers and quantum computation. Therefore, it is of great interest to realize such nonclassical states with matter waves. Bose-Einstein condensates with non-zero spin can provide a mechanism analogous to parametric down conversion, thus enabling the generation of nonclassical matter waves. The process acts as a two-mode parametric amplifier and generates two clouds with opposite spin orientation consisting of the same number of atoms. At a total of ~10000 atoms, we observe a squeezing of the number difference of -7 dB below shot noise, including all noise sources. A microwave coupling between the two modes allows for an investigation of the interferometric sensitivity. We find that the created state is entangled and useful for sub-shot-noise interferometry. Jacob Sherson and Aurélien Dantan Coffee, tea and cake will be served at 15.05 ----------------------------------- Aurelien Dantan Ion Trap Group Department of Physics and Astronomy University of Aarhus Ny Munkegade, bygn. 1520 8000 Aarhus Denmark +4589423602