Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Journal of Physics B Atomic and Molecular Physics

Spectral line broadening due to the interaction between very excited atoms: 'the dense Rydberg gas'

J. M. Raimond, Guy Vitrant, S. Haroche

Published Nov 14, 1981• 81 citations
Publisher

Abstract

The authors report the first observation of spectral line perturbations, due to van der Waals coupling between very excited atoms, in a sample where the average interatomic distance is about 15 times the Rydberg atom radius. Broadenings of the order of intervals between adjacent lines reveal Rydberg-Rydberg couplings no longer negligible compared with the atomic binding energy. The authors analyse the excitation mechanism of this 'dense Rydberg gas' by laser light non-resonant for the unperturbed atoms.

DOI
10.1088/0022-3700/14/21/003

Related papers

Suppression of Excitation and Spectral Broadening Induced by Interactions in a Cold Gas of Rydberg Atoms

Kilian Singer, M. Reetz‐Lamour, Thomas Amthor +2 more

We report on the observation of ultralong range interactions in a gas of cold rubidium Rydberg atoms. The van der Waals interaction between a pair of Rydberg atoms separated as far as 100,000 Bohr radii features two important effects: spectral broadening of the resonance lines and suppression of excitation with increasing density. The density dependence of these effects is investigated in detail for the S- and P-Rydberg states with principal quantum numbers n approximately 60 and n approximately 80 excited by narrow-band continuous-wave laser light. The density-dependent suppression of excitation can be interpreted as the onset of an interaction-induced local blockade.

arXiv:physics/0404075•Physical Review Letters•Oct 13, 2004•411 citations

Ultralong-Range Interactions and Blockade of Excitation in a Cold Rydberg Gas

Matthias Weidemüller

We review our recent experiments on interaction‐induced effects in a gas of Rydberg atoms excited from a laser‐cooled rubidium cloud. The van‐der‐Waals interaction between a pair of Rydberg atoms separated as far as 100,000 Bohr radii features two important effects: Spectral broadening of the resonance lines and suppression of excitation with increasing Rydberg density. The line broadenings are interpreted in terms of level shifts of Rydberg pairs due to their interaction. The density‐dependent suppression of excitation marks the onset of an interaction‐induced local blockade.

AIP conference proceedings•Jan 1, 2005•1 citation

Rydberg-Rydberg interaction in the second-harmonic generation from rubidium atoms

Natalia R. de Melo, S. S. Vianna

We report on the observation of long range interaction in the second-harmonic generation from rubidium Rydberg atoms. The asymmetric spectral broadening of the resonant lines provides evidence of the van der Waals interaction between pairs of Rydberg atoms. This effect is investigated when the two-photon transition is resonant with $nd$ levels for $n\ensuremath{\approx}13$.

Physical Review A•Feb 27, 2008•1 citation

Long-Range Molecular Resonances in a Cold Rydberg Gas

S. M. Farooqi, D. Tong, S. Krishnan +8 more

We present evidence for molecular resonances in a cold dense gas of rubidium Rydberg atoms. Single UV photon excitation from the 5s ground state to np Rydberg states (n=50-90) reveals resonances at energies corresponding to excited atom pairs (n-1)d+ns. We attribute these normally forbidden transitions to avoided crossings between the long-range molecular potentials of two Rydberg atoms. These strong van der Waals interactions result in avoided crossings at extremely long range, e.g., approximately 58 000 times the Bohr radius (a(0)) for n=70.

Physical Review Letters•Oct 31, 2003•118 citations

Long-range interactions in a cold Rydberg gas

P. L. Gould, S. M. Farooqi, D. Tong +5 more

The excitation of cold Rydberg atoms is significantly influenced by long-range van der Waals interactions. Avoided crossings between interatomic potentials lead to molecular resonances, while energy level shifts from neighboring atoms suppress resonant Rydberg excitation.

Quantum Electronics and Laser Science Conference•Dec 10, 2005•0 citations

Long-Range Interactions in an Ultracold Rubidium Rydberg Gas

D. Tong

New phenomena have been observed by exciting ultracold ground-state atoms to Rydberg states. Starting with a dense sample of Rb atoms in a magneto-optical trap, we excite them to high Rydberg states (n = 30 - 90) with a single UV excitation pulse. Long-range molecular resonances with interatomic distances exceeding 104 a0 have been discovered. We have also observed the Rydberg excitation blockade, crucial for the implementation of quantum phase gates using neutral atoms. The physics behind these observations is attributed to the strong long-range van der Waals interactions among the Rydberg atoms. In addition, we have seen dipole (E1) forbidden but quadrupole (E2) allowed 5s → nd transitions, allowing us to determine the E2 oscillator strengths to these high Rydberg states. Our narrow-band UV pulsed laser system, with ∼100 MHz bandwidth, also allows us to measure the ratios of j-dependent oscillator strengths to the p and d Rydberg states. ^

•Jan 1, 2010•0 citations
The authors report the first observation of spectral line perturbations, due to van der Waals coupling between very excited atoms, in a sample where the average interatomic distance is about 15 times the Rydberg atom radius. Broadenings of the order of intervals between adjacent lines reveal Rydberg-Rydberg couplings no longer negligible compared with the atomic binding energy. The authors analyse the excitation mechanism of this 'dense Rydberg gas' by laser light non-resonant for the unperturbed atoms.
We report on the observation of ultralong range interactions in a gas of cold rubidium Rydberg atoms. The van der Waals interaction between a pair of Rydberg atoms separated as far as 100,000 Bohr radii features two important effects: spectral broadening of the resonance lines and suppression of excitation with increasing density. The density dependence of these effects is investigated in detail for the S- and P-Rydberg states with principal quantum numbers n approximately 60 and n approximately 80 excited by narrow-band continuous-wave laser light. The density-dependent suppression of excitation can be interpreted as the onset of an interaction-induced local blockade.
We review our recent experiments on interaction‐induced effects in a gas of Rydberg atoms excited from a laser‐cooled rubidium cloud. The van‐der‐Waals interaction between a pair of Rydberg atoms separated as far as 100,000 Bohr radii features two important effects: Spectral broadening of the resonance lines and suppression of excitation with increasing Rydberg density. The line broadenings are interpreted in terms of level shifts of Rydberg pairs due to their interaction. The density‐dependent suppression of excitation marks the onset of an interaction‐induced local blockade.
We report on the observation of long range interaction in the second-harmonic generation from rubidium Rydberg atoms. The asymmetric spectral broadening of the resonant lines provides evidence of the van der Waals interaction between pairs of Rydberg atoms. This effect is investigated when the two-photon transition is resonant with ndndnd levels for $n\ensuremath{\approx}13$.
We present evidence for molecular resonances in a cold dense gas of rubidium Rydberg atoms. Single UV photon excitation from the 5s ground state to np Rydberg states (n=50-90) reveals resonances at energies corresponding to excited atom pairs (n-1)d+ns. We attribute these normally forbidden transitions to avoided crossings between the long-range molecular potentials of two Rydberg atoms. These strong van der Waals interactions result in avoided crossings at extremely long range, e.g., approximately 58 000 times the Bohr radius (a(0)) for n=70.
New phenomena have been observed by exciting ultracold ground-state atoms to Rydberg states. Starting with a dense sample of Rb atoms in a magneto-optical trap, we excite them to high Rydberg states (n = 30 - 90) with a single UV excitation pulse. Long-range molecular resonances with interatomic distances exceeding 104 a0 have been discovered. We have also observed the Rydberg excitation blockade, crucial for the implementation of quantum phase gates using neutral atoms. The physics behind these observations is attributed to the strong long-range van der Waals interactions among the Rydberg atoms. In addition, we have seen dipole (E1) forbidden but quadrupole (E2) allowed 5s → nd transitions, allowing us to determine the E2 oscillator strengths to these high Rydberg states. Our narrow-band UV pulsed laser system, with ∼100 MHz bandwidth, also allows us to measure the ratios of j-dependent oscillator strengths to the p and d Rydberg states. ^