Van der Waals Interactions among Alkali Rydberg Atoms with Excitonic States

Abstract

We investigate the influence of the appearance of excitonic states on van der Waals interactions among two Rydberg atoms. The atoms are assumed to be in different Rydberg states, e.g., in the $|ns⟩$ and $|np⟩$ states. The resonant dipole-dipole interactions yield symmetric and antisymmetric excitons, with energy splitting that give rise to new resonances as the atoms approach each other. Only far from these resonances the van der Waals coefficients, $C_6^{sp}$, can be defined. We calculate the $C_6$ coefficients for alkali atoms and present the results for lithium by applying perturbation theory. At short interatomic distances of several $\mu m$, we show that the widely used simple model of two-level systems for excitons in Rydberg atoms breaks down, and the correct representation implies multi-level atoms. Even though, at larger distances one can keep the two-level systems but in including van der Waals interactions among the atoms.

9 pages, 9 figures

References in corpus (5)

• Coherent Excitation Transfer in a Spin Chain of Three Rydberg Atoms
• Coherent dipole-dipole coupling between two single atoms at a Förster resonance
• Newton's cradle and entanglement transport in a flexible Rydberg chain
• Motion of Rydberg atoms induced by resonant dipole-dipole interactions
• Excitons and cavity polaritons for ultracold atoms in an optical lattice

Cited by in corpus (6)

• Possible many-body localization in a long-lived finite-temperature ultracold quasi-neutral molecular plasma
• Tailoring Rydberg interactions via Förster resonances: state combinations, hopping and angular dependence
• Many-body physics with ultracold plasmas: Quenched randomness and localization
• Dynamical phases in a one-dimensional chain of Heterospecies Rydberg atoms with next-nearest neighbor interactions
• Switchable dynamic Rydberg-dressed excitation via a cascaded double electromagnetically induced transparency
• Dynamical control in a prethermalized molecular ultracold plasma: Local dissipation drives global relaxation