Polyatomic Rydberg molecules: from bound states to resonant energy transfer

Hybrid systems combining Rydberg atoms and polar molecules provide a unique platform to explore quantum effects mediated by the charge-dipole interaction. This anisotropic interaction is due to the coupling between the electric field produced by the Rydberg electron and atomic core with the electric dipole moment of the molecule, and gives rise to different physical phenomena depending on the separation between both systems. When the diatomic polar molecule is immersed into the wave function of the excited atom, the anisotropic scattering of the Rydberg electron from the electric dipole moment of the dimer is the binding mechanism to create Rydberg molecules [1,2]. We will explore the electronic structure and main properties of ultralong-range molecules formed from different Rydberg systems [3-4], and how to facilitate their experimental creation. When the molecule is located in the tail of the Rydberg electron wave function, the charge-dipole interaction can blockade the atomic Rydberg excitation. The Rydberg blockade has been experimentally observed by confining the atom and molecule in optical tweezers and exciting the rubidium atom to a Rydberg state [5]. In this talk, we will show that the theoretical results using the electronic structure of the Rydberg molecule Rb-RbCs reproduce the observed excitation dynamics [5]. Under resonant conditions, the charge-dipole interaction can mediate nondestructive readout, quantum information processing, and energy transfer. In this regime, we will present the theoretical description of the resonant energy transfer between two equal parity Rydberg levels of helium with ammonia molecules, undergoing inversion transition, experimentally observed at low temperature [6]. We show that the spatial overlap of the Rydberg-electron and molecular wave functions is required for the monopole-dipole energy exchange reaction to occur. 

[1] S.T. Rittenhouse & H.R. Sadeghpour, Phys. Rev. Lett. 104, 243002 (2010). 

[2] R. González-Férez et al, New J. Phys. 17, 013021 (2015). 

[3] R. González-Férez et al, Phys. Rev. Lett. 126, 043401 (2021). 

[4] D.Mellado-Alcedo et al, Phys. Rev. A 110, 013314 (2024). 

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

[6] J. Zou et al, arXiv:2509.21582