Yb Atom Interferometers within an Optical Lattice: Multi-path Stuckelberg and Magic Depth Interferometry*

We report on multi-path Stuckelberg (MPS) interferometry in an ultracold atom system. Our atomic source is a BEC of {^174}Yb which is loaded into an optical lattice made from two counter-propagating laser beams with tunable frequency sweep suitable for an atom interferometer (AI) in a vertical fountain geometry [1]. The frequency sweep drives Bloch oscillations (BOs) of atomic momentum wherein the avoided crossing corresponding to each BO process is effectively a beam splitter where a Landau-Zener tunneling event between adjacent bands can occur, forming an in-lattice AI with 2^(N-1) paths where N is the number of BOs. We use MPS AIs to characterize BO phase shifts for precision interferometry [2]. We plan to extend in-lattice interferometry by pairing with operation at “magic depths”, where the average band energy is first-order insensitive to lattice depth fluctuations from intensity noise of the lattice beams [3]. Such magic-trapped atom interferometry can be applied towards precision gravimetry and equivalence principle tests.

1. D. Gochnauer et al Atoms 9, 58 (2021) 

2. T. Rahman et al (in preparation)

3. K. McAlpine et al, Phys. Rev. A 101, 023614 (2020)