Polyatomic ultralong-range Rydberg molecules; Electronic structure and Rydberg blockade

Rosario González-Férez Universidad de Granada

Rydberg atoms have played a crucial role in the birth of quantum mechanics [1,2], and scattering theory as well as in the development of high precision spectroscopic techniques [3]. Due to their exotic properties, Rydberg atoms are unique probes of their environment, which can be easily controlled and manipulated using electromagnetic fields. In addition, Rydberg atoms also form exotic ultralong-range molecules when combined with ground-state atoms [4,5], ions [6], or polar molecules [7,8], which inherit these exciting properties. We will explore the interaction of a polar molecule with a Rydberg atom creating a polyatomic Rydberg molecule [8,9]. Our focus is the regime where the charge-dipole interaction of the Rydberg electron with the molecular electric dipole moment induces a coupling between the quantum defect states and the nearest degenerate hydrogenic manifold [8-10]. Based on these non-adiabatic couplings, we propose a protocol to create the Rydberg molecules experimentally in a mixture of ultracold atoms and ultracold molecules [10]. We will also present the first experimental demonstration of the Rydberg blockade due to this charge-dipole interaction between a Rb atom and a RbCs molecule [11]. The atom and molecule are confined in optical tweezers, and for a separation of 310 nm, the charge-dipole interaction between the Rydberg electron and atomic core with the dipole moment of RbCs provokes the blockade of the transition to the Rb Rydberg state. The observed excitation dynamics are in excellent agreement with the theoretical results obtained using the electronic structure of the Rydberg molecule Rb-RbCs [11]

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[11] A. Guttridge, et al, Phys. Rev. Lett. 131, 013401 (2023).