The recent experimental realization of a three-dimensional (3D) optical lattice clock not only reduces the influence of collisional interactions on the clock's accuracy but also provides a promising platform for studying dipolar many-body quantum physics. Here, by solving the governing master equation, we investigate the role of both elastic and dissipative long-range interactions in the clock's dynamics and study its dependence on lattice spacing, dimensionality, and dipolar orientation. For small lattice spacing, i.e., ${k}_{0}a\ensuremath{\ll}1$, where
a is the lattice constant and
k0 is the transition wave number, a sizable spin squeezing appears in the transient state which is favored in a head-to-tail dipolar configuration in 1D systems and a side-by-side configuration in 2D systems, respectively. For large lattice spacing, i.e., ${k}_{0}a\ensuremath{\gg}1$, the single atomic decay rate can be effectively suppressed due to the destructive dissipative emission of neighboring atoms in both 1D and 2D. Our results will not only aid in the design of the future generation of ultraprecise atomic clocks but also illuminates the rich many-body physics exhibited by radiating dipolar system.
We report on the observation of a high-density, band insulating state in a three-dimensional optical lattice clock. Filled with a nuclear-spin-polarized degenerate Fermi gas of
87Sr, the three-dimensional (3D) lattice has one atom per site in the ground motional state, thus guarding against frequency shifts due to contact interactions. At this high density where the average distance between atoms is comparable to the probe wavelength, conventional imaging techniques at saturation intensity suffer from large systematic errors. To spatially probe frequency shifts in the clock and measure thermodynamic properties of this system, accurate imaging techniques at high optical depths are required. Using a combination of highly saturated fluorescence and absorption imaging, we confirm the density distribution in our 3D optical lattice in agreement with a single spin band insulating state. Combining our clock platform with this high filling fraction opens the door to studying new classes of long-lived, many-body states arising from dipolar interactions.
We study dipolar relaxation of a chromium BEC loaded into a 3D optical lattice. We observe dipolar relaxation resonances when the magnetic energy released during the inelastic collision matches an excitation towards higher energy bands. A spectroscopy of these resonances for two orientations of the magnetic field provides a 3D band spectroscopy of the lattice. The narrowest resonance is registered for the lowest excitation energy. Its line-shape is sensitive to the on-site interaction energy. We use such sensitivity to probe number squeezing in a Mott insulator, and we reveal the production of three-body states with entangled spin and orbital degrees of freedom.