[EQuAL] Rydberg Atoms in Bose–Einstein Condensates

Speaker: Madeleine Bow Jun Leibovitch

Title: “Rydberg Atoms in Bose–Einstein Condensates”

Abstract:

Atoms with an electron excited to a very high principal quantum number are called Rydberg atoms. Rydberg atoms have exaggerated properties such as a large electron orbital radius and strong long-range interactions, making them a leading tool for quantum control in neutral-atom systems. Beyond their use for implementing entangling gates in quantum computing platforms, Rydberg excitations inside Bose–Einstein condensates (BECs) give rise to unique phenomena. When a Rydberg atom is excited inside a BEC, its weakly bound electron scatters off the surrounding ground-state atoms, creating an attractive potential that can bind atoms into exotic Rydberg molecules or dress the Rydberg atom into a Rydberg polaron.

In this talk, I will describe our effort to study these phenomena using small potassium-39 BECs of a few thousand atoms prepared in optical tweezers. I will introduce our two-photon Rydberg excitation scheme and initial vapor cell spectroscopy procedures. Finding the Rydberg resonance in a hot vapor cell for our excitation scheme proved surprisingly difficult: in this “inverted” wavelength configuration, Doppler shifts wash out the usual electromagnetically induced transparency (EIT) signal. I will detail this challenge using simulations of the atomic populations and show how velocity-selective EIT spectroscopy is used to mitigate it. Finally, I will present our first Rydberg spectroscopy results in ultracold potassium, where we resolve molecular signals. I will discuss our plans to use these as a starting point for further probing Rydberg molecules and polarons in BECs, and their applications to the control of quantum many-body systems.

The Exploring Quantum Assembly at Lunch (EQuAL) seminar is jointly funded by the Eddleman Quantum Institute, the InTriQATe NSF Research Traineeship (NRT), and the Quantum Foundry.

Fall quarter 2026 is generously funded by the InTriQATe NRT.

The Integrative Training in Quantum Assembly and Technology (InTriQATe) NSF Research Traineeship (NRT) aims to support and inspire the next generation of quantum scientists by providing innovative opportunities for training and professional development in an interdisciplinary collaborative context.