Lattice Atom Interferometry (LATIN)

Atom interferometers have enabled us to measure forces with exceptionally high precision. Inevitably, these forces are averaged over the free-fall trajectory of the atoms, up to 10 meters, taking advantage of the quadratic scaling of sensitivity with time of flight. This precludes measurements of localized forces, such as Casimir-Polder forces, or proposed short range interactions of physics beyond the standard model. To shrink these distances, interferometers have held atoms against gravity in optical lattices but were severely limited by dephasing due to speckles and other imperfections of the laser beams. At UC Berkeley, I have developed atom interferometers with laser beams that are resonantly enhanced and mode-filtered in an optical cavity. Here, I propose to bring this new and promising idea of lattice interferometry to a completely new level, using a far off-resonant optical lattice in a high-finesse cavity. This will enable ultra-long interferometry times (up to 10 sec) and push the sensitivity and capabilities of atom interferometry by many orders of magnitude. I will add distinct features like a dichromatic cavity for versatile atom manipulation, an advanced source for ultracold atomic samples, and detection with single lattice site resolution. This will allow for running simultaneous atom interferometers in up to 100 adjacent lattice sites, which will enable us to map the local potential landscape with ~1 m resolution. These advances will empower us to: (1) Search for new physics: The observed dark matter/energy content of the universe motivates several classes of theories which result in a force acting on atoms near surfaces. At similar length scales, string theory and other unification theories predict putative deviations from Newtons inverse square law of gravity. Searching for such exotic forces requires precise characterization of atom-surface interactions induced by quantum vacuum fluctuations e.g. van der Waals-London, Casimir-Polder, and thermal-radiation induced forces. This will isolate possible contributions of exotic forces, while providing insight into the physics of quantum atom- surface interactions. (2) Investigate optically-induced inter-particle interactions: These interactions cause self-organization of atoms and nanoparticles into freely propagating optically-bound particles, which paves the way for exploring quantum interference of complex multi-atom systems. LATIN will enable the investigation of interference effects with interacting ensembles of atoms exploring a variety of novel light induced collective phenomena. LATIN will bring the sensitivity and spatial resolution of atom interferometry to a new level, allowing for exploration of exotic forces beyond the standard model, enhancing our understanding of quantum fluctuation-driven interactions, and enabling investigation of optically induced interactions between atoms as a means to further improve the sensitivity of matter-wave interferometry.