Observation of dipole-quadrupole interaction in an ultracold gas of Rydberg atoms

Abstract

We observe the direct excitation of pairs of Cs atoms from the ground state to molecular states correlating asymptotically to $ns{n}^{\prime }f$ asymptotes. The molecular resonances are interpreted as originating from the dipole-quadrupole interaction between the $ns{n}^{\prime }f$ pair states and close-by $npnp$ asymptotes ($22\le n\le 32$). This interpretation is supported by Stark spectroscopy of the pair states and a detailed modeling of the interaction potentials. The dipole-quadrupole interaction mixes electronic states of opposite parity and thus requires a coupling between electronic and nuclear motion to conserve the total parity of the system. This non-Born-Oppenheimer coupling is facilitated by the near-degeneracy of even and odd $L$ partial waves in the atom-atom scattering which have opposite parity.

5 pages, 3 figures

References in corpus (3)

• Diamondoid Molecules
• Consequences of Zeeman Degeneracy for van der Waals Blockade between Rydberg Atoms
• Long-range potentials and $(n-1)d+ns$ molecular resonances in an ultracold rydberg gas

Cited by in corpus (8)

• Experimental characterization of singlet scattering channels in long-range Rydberg molecules
• Observation of Rydberg-atom macrodimers: micrometer-sized diatomic molecules
• Long-range Rydberg-atom-ion molecules of Rb and Cs
• Rydberg-State-Resolved Resonant Energy Transfer in Cold Electric-Field-Controlled Intrabeam Collisions of NH${}_3$ with Rydberg He Atoms
• Measurement of Rb g-series quantum defect using two-photon microwave spectroscopy
• Non-adiabatic decay of Rydberg-atom-ion molecules
• Rydberg Macrodimers: Diatomic molecules on the micrometer scale
• Microwave photo-association of fine-structure-induced Rydberg $(n+2)D_{5/2}n{F}_J$ macro-dimer molecules of cesium