Bloch oscillation phases investigated by multipath Stückelberg atom interferometry

Atoms undergoing Bloch oscillations (BOs) in an accelerating optical lattice acquire momentum of two photon recoils per BO. This technique provides a large momentum transfer tool for atom optics, but its full exploitation for atom interferometric sensors requires both experimental and theoretical characterization of associated phases. Each BO involves a Landau-Zener crossing with multiple crossings inducing interference known as Stückelberg interference. We develop a multipath Stückelberg interferometer and investigate atomic phase evolution during BOs, up to 100 photon recoil momentum transfer. We compare to numerically calculated single-particle Schrödinger evolution, demonstrate highly coherent BO sequences, and assess phase stability requirements for BO-enhanced precision interferometry in fundamental physics and sensing applications.