A Rydberg/cavity QED apparatus for exploring polariton blockade

In this work, we present the technical advances that have enabled us to explore Rydberg-mediated Interactions between resonator photons. In particular, we describe an exotic resonator geometry that enables us to maintain ~the small mode waist essential for exploring blockade physics, while keeping all material surfaces nearly a full cm away from the electric-field sensitive Rydbergs. We achieve stray fields stable at the 10mV/cm level over a day, in spite of the presence of a high-voltage piezo actuator to stabilize the resonator length to the few angstrom level. This enables us to employ 87Rb Rydbergs in the n$=$\textit121S quantum state, with a DC polarizability of nearly 24GHz/(v/cm)\textasciicircum 2, for our cavity Rydberg EIT experiments, thereby reaching the blockaded regime, indicating strong interactions between individual photons. We will also explore prospects for pushing these experiments into a multimode regime where dissipative manybody pumping will allow us to explore crystals and topological fluids of photons.