A new apparatus to study Rydberg synthetic dimensions

Rydberg atom-microwave interactions are important in many areas of Rydberg physics ranging from Rydberg synthetic dimensions to micromasers. In this work we describe progress on a new apparatus developed to study Rydberg atom-microwave interactions that, guided by finite element analysis (FEA) simulations, was designed specifically to minimize spurious reflections which can change both the amplitude and polarization of the applied fields. In measurements presented here, atoms are first excited from a blue magneto-optical trap (MOT) to the 1P1 state and subsequently excited to a Rydberg state from ¹D₂ states (n=55–61) with two-photon excitation using 461nm and 413 nm light. Coupling between the D and nearby states is achieved through two-photon mm wave excitation delivered via a horn antenna. To assess the chamber’s performance against simulation predictions, we measure the Rabi frequency and polarization purity of the applied mm waves using the Rydberg-Rydberg transition. By correlating these measurements with simulation results, we gain insights into the chamber’s ability to deliver mm waves with high polarization purity, a critical factor for advancing mm wave-based quantum control in our ultracold Rydberg systems.