**Quantum interference of expanding BEC in microgravity**

Institut fur Quantenphysik, Universitat Ulm

Interferometry with expanding Bose-Einstein condensate in microgravity can be exploited to probe fundamental physics at the border between quantum mechanics and general relativity.

In particular millions of atoms in a BEC can be described by a single macroscopic wave function which oers itself for quantum interference experiments aimed to test the weak equivalence principle.

In this talk I will describe the physics behind the BEC expansion and interference in microgravity in the time-dependent Thomas-Fermi (TF) regime in generic interferometric congurations and taking into account rst order corrections in perturbation theory.

In particular, by using an asymmetric Mach-Zehender conguration interference fringes for expanding BEC in microgravity have been recently observed in pioneering experiments within our QUANTUS collaboration

[1]. Such experiments not only represent a perfect test for future experiments in orbit but also gives us an important motivation in pursuing further exciting research based on quantum gravimeters for ground based applications.

[1] 1. H. Muentinga, et al., Phys. Rev. Lett. 110, 093602 (2013) (Viewpoint: M. Arndt, Physics 6, 23 (2013)).

Location: Physics Bldg., Room 401