Petrucciani, Tommaso — Spatial Bloch oscillations of a quantum gas in a “beat-note” superlattice

In this work, I report the realization of a novel optical lattice for the manipulation of ultra-cold atoms, where
arbitrarily large separation between the sites can be achieved without renouncing to the stability of retroreflected lattices. Superimposing two short-wavelength optical lattices with commensurated wavelengths,
about 1µm each, I realize an intensity periodic pattern with a beat-note like profile where the regions with
high amplitude modulation provide the potential minima for the atoms, which experience an effective
lattice period around 10 µm. I employ a Bose-Einstein condensate to measure the energy gaps between the
first three bands and study in-trap Bloch oscillation with negligible interaction in presence of small external
forces. The long-lasting (1 second) oscillations between sites separated by 10 µm I report prove the high
stability of this potential and it is a valuable tool for the precise manipulation of atoms at large distances in
a wide range of applications, for example, trapped atom interferometry.