Full 3D Simulations of Guided BEC Interferometers

Atom interferometry has grown into a successful tool for precision measurements since the pioneering works of  Steven Chu and Mark Kasevich [1, 2]. Experiments with record-breaking precision have been performed in the fields of inertial sensing and tests of the foundations of physics. These high precision measurements are achieved either by large momentum transfer (LMT) or long interrogation times. Recently, the former technique has led to a state-of-the-art separation of more than 400 hbark [3]. In this experiment, Bose-Einstein Condensates (BECs) are used to further enhance precision atom interferometry thanks to the intrinsically large coherence and narrow momentum width. In this talk, we present a newly developed numerical toolbox to solve the time-dependent Gross-Pitaevskii equation in 3D. To demonstrate its capability, we study BEC interferometers realized in both free-fall and guided geometry and compare our results with experimental data. We specifically investigate the guided expansion and double-Bragg diffraction (DBD) of a BEC by two retro-reflected laser beams in a real-time evolution. Finally, we present a phase scan of a fully guided Mach-Zehnder interferometer based on DBD.

[1] Kasevich M. and Chu S., Phys. Rev. Lett., 67 (1991) 181.

[2] Kasevich M. and Chu S., Appl. Phys. B, 54 (1992) 321.

[3] Gebbe, M., Siemß, JN., Gersemann, M. et al., Nat Comm., 12, (2021) 2544.