Condensate interferometer on an atom chip

Ying-Ju Wang

Dana Z. Anderson

Thorsten Schumm, P. Krüger, Sebastian Hofferberth +6 more

Carlos L. Garrido Alzar, Wenhua Yan, Satyanarayana Bade +2 more

Ying-Ju Wang, Dana Z. Anderson, Victor M. Bright +7 more

An atom Michelson interferometer is implemented on an "atom chip." The chip uses lithographically patterned conductors and external magnetic fields to produce and guide a Bose-Einstein condensate. Splitting, reflecting, and recombining of condensate atoms are achieved by a standing-wave light field having a wave vector aligned along the atom waveguide. A differential phase shift between the two arms of the interferometer is introduced by either a magnetic-field gradient or with an initial condensate velocity. Interference contrast is still observable at 20% with an atom propagation time of 10 ms.

Matthieu Dupont-Nivet, Christoph Ira Westbrook, Sylvain Schwartz

Cold atom interferometers have demonstrated excellent performance and hold great prospects for time, gravity, acceleration and rotation measurements [1]. Trapped interferometers, for example using atom chips [2], can potentially enable portable applications of theses sensors. Atom chip interferometers have been successfully demonstrated using Bose-Einstein condensates [3] but are subject to the effect of atom-atom interactions which cause phase decoherence [4]. In [5], we proposed an atom chip interferometer using a gas just above the condensation threshold to reduce the interaction effects. This proposal is similar to white light interferometry in the sense that the difference between the optical paths of the two arms must be close to zero to observe fringes. In a trapped interferometer this condition is analogous to maximizing the degree of symmetry between the two trapping potentials [6]. We demonstrated that if the two trapping potentials are harmonic with slightly different curvatures (ω and ω + δω for the first and the second trap) inhomogeneous dephasing arises.