Probing and controlling many-body interactions in a simple cubic optical lattice clock

Recent advances in optical atomic clocks have enabled frequency measurements beyond eighteen digits of accuracy. In addition to providing the backbone of the International System of Units, atomic clocks are powerful quantum sensors when applied to tests of fundamental physics including searches for ultralight dark matter and tests of general relativity.
Towards the goal of further improving measurement precision, I will describe recent experiments in a quantum gas optical atomic clock capable of interrogating tens-of-thousands of atoms with optical coherence times exceeding 10 seconds.

In particular, I will describe our investigation into a new systematic effect, the cooperative Lamb shift. We will show that this many-dipole analogue to the well known Lamb shift is enhanced by the relatively high atomic density in the quantum gas, and can either be made large, or negligibly small as compared to total systematic uncertainties of other state-of-the-art optical clocks, depending on exact details of the spectroscopic sequence and lattice geometry. Beyond informing future metrological applications, further studies of these interactions are expected to reveal a novel many-body system involving interacting spin-waves with non-trivial band-structures.