Peter Reynolds, Army Research Office
“Chemistry, electronics, lattice models and more -- in thin air: A story about optical lattices”

I will describe how the advent of laser cooling and trapping of atoms and ions progressed to the achievement of quantum degeneracy in ultra-dilute atomic gases, and then to their trapping in optical lattices. These incredibly dilute gases can be used in a variety of unexpected ways, from altering chemical reaction dynamics, to serving as concept atomtronic devices (generalizing electronics with the many additional degrees of freedom afforded by atoms), to the creation of physical embodiments of model Hamiltonians. The latter is an intriguing way to “solve&edquo; numerically intractable models such as the Fermi Hubbard model, believed to be at the heart of high-temperature superconductivity. Trapping molecules in optical lattices opens even more opportunities. Competing phases are expected to be realized with the introduction of long-ranged dipolar interactions. Because the strength of the dipole moment is a key parameter in this competition, it is necessary to know its value for the molecules that might be cooled and trapped in future optical lattice experiments. To this end, we have computed the dipole moment for some specific molecules of interest because they are candidates for such experiments. In particular, LiSr is extremely weakly bound and has never been made, yet has desirable properties of coupling by both electric and magnetic interactions. Traditional methods of computing the binding energy and the dipole moment converge very poorly for this molecule. We employ a quantum Monte Carlo approach, which is considered the gold standard for accuracy. This approach and our results will be discussed.