Physical Review Letters

Repulsive van der Waals and Dipole-Quadrupole Interaction in the Excited LiCs Molecule

Cedomil Vadla, Claus J. Lorenzen, Kay Niemax

Published Sep 12, 1983• 15 citations

Abstract

The authors report strong repulsive van der Waals and dipole-quadrupole interactions in the $\ensuremath{\Sigma}$ and $\ensuremath{\Pi}$ potentials of the LiCs molecule dissociating into Li $2P$ and Cs $6S$ atoms. Theoretical results derived from second-order perturbation theory are verified by investigating experimentally the wavelength dependence of the quasistatic wings of the Li resonance lines broadened by Cs ground-state atoms.

DOI: 10.1103/physrevlett.51.988

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Physical Review Letters

Repulsive van der Waals and Dipole-Quadrupole Interaction in the Excited LiCs Molecule

Cedomil Vadla, Claus J. Lorenzen, Kay Niemax

Published Sep 12, 1983• 15 citations

Publisher

Abstract

The authors report strong repulsive van der Waals and dipole-quadrupole interactions in the

\ensuremath{\Sigma}

and

\ensuremath{\Pi}

potentials of the LiCs molecule dissociating into Li

2P

and Cs

6S

atoms. Theoretical results derived from second-order perturbation theory are verified by investigating experimentally the wavelength dependence of the quasistatic wings of the Li resonance lines broadened by Cs ground-state atoms.

DOI: 10.1103/physrevlett.51.988

Related papers

Transition from second- to first-order dipole-dipole interaction in the excited EuSr molecule

Kay Niemax

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C6 coefficients for interacting Rydberg atoms and alkali-metal dimers

V. C. Olaya-Agudelo, Jesús Pérez‐Ríos, Felipe Herrera

We study the van der Waals interaction between Rydberg alkali-metal atoms with fine structure ( ${n}^{2}{L}_{j}$ ; $L\ensuremath{\le}2$) and heteronuclear alkali-metal dimers in the ground rovibrational state ($X^{1}\mathrm{\ensuremath{\Sigma}}^{+}$; $v=0, J=0$ ). We compute the associated ${C}_{6}$ dispersion coefficients of atom-molecule pairs involving $^{133}\mathrm{Cs}$ and $^{85}\mathrm{Rb}$ atoms interacting with KRb, LiCs, LiRb, and RbCs molecules. The obtained dispersion coefficients can be accurately fitted to a state-dependent polynomial $O({n}^{7})$ over the range of principal quantum numbers $40\ensuremath{\le}n\ensuremath{\le}150$. For all atom-molecule pairs considered, Rydberg states $n^{2}S_{j}$ and $n^{2}P_{j}$ result in attractive $1/{R}^{6}$ potentials. In contrast, $n^{2}D_{j}$ states can give rise to repulsive potentials for specific atom-molecule pairs. The interaction energy at the LeRoy distance approximately scales as ${n}^{\ensuremath{-}5}$ for $n>40$ . For intermediate values of $n\ensuremath{\lesssim}40$, both repulsive and attractive interaction energies of the order of 10--$1000\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\mathrm{K}$ can be achieved with specific atomic and molecular species. The accuracy of the reported ${C}_{6}$ coefficients is limited by the quality of the atomic quantum defects, with relative errors $\mathrm{\ensuremath{\Delta}}{C}_{6}/{C}_{6}$ estimated to be no greater than 1% on average.We study the van der Waals interaction between Rydberg alkali-metal atoms with fine structure (${n}^{2}{L}_{j}$; $L\ensuremath{\le}2$) and heteronuclear alkali-metal dimers in the ground rovibrational state ($X^{1}\mathrm{\ensuremath{\Sigma}}^{+}$; $v=0, J=0$). We compute the associated ${C}_{6}$ dispersion coefficients of atom-molecule pairs involving $^{133}\mathrm{Cs}$ and $^{85}\mathrm{Rb}$ atoms interacting with KRb, LiCs, LiRb, and RbCs molecules. The obtained dispersion coefficients can be accurately fitted to a state-dependent polynomial $O({n}^{7})$ over the range of principal quantum numbers $40\ensuremath{\le}n\ensuremath{\le}150$. For all atom-molecule pairs considered, Rydberg states $n^{2}S_{j}$ and $n^{2}P_{j}$ result in attractive $1/{R}^{6}$ potentials. In contrast, $n^{2}D_{j}$ states can give rise to repulsive potentials for specific atom-molecule pairs. The interaction energy at the LeRoy distance approximately scales as ${n}^{\ensuremath{-}5}$ for $n>40$. For intermediate values of $n\ensuremath{\lesssim}40$, both repulsive and attractive interaction energies of the order of 10--$1000\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\mathrm{K}$ can be achieved with specific atomic and molecular species. The accuracy of the reported ${C}_{6}$ coefficients is limited by the quality of the atomic quantum defects, with relative errors $\mathrm{\ensuremath{\Delta}}{C}_{6}/{C}_{6}$ estimated to be no greater than 1% on average.

arXiv:1912.01568Physical Review AMar 23, 20206 citations

The authors report strong repulsive van der Waals and dipole-quadrupole interactions in the

\ensuremath{\Sigma}

and

\ensuremath{\Pi}

potentials of the LiCs molecule dissociating into Li

2P

and Cs

6S

{\mathrm{}}^{8}

{\mathrm{P}}_{9/2}

and strontium 5

{\mathrm{s}}^{2}

{\mathrm{}}^{1}

{\mathrm{P}}_{1}

atoms. The transition was verified by measurement of the wavelength dependence in the quasistatic wings of the cw-laser--excited 4595.3-A\r{} line in Eu broadened by Sr ground-state atoms.

{}_{2}

, showing that the photoassociation is probably efficient for any Cs

{}_{2}

rotational energy.

We study the van der Waals interaction between Rydberg alkali-metal atoms with fine structure (

{n}^{2}{L}_{j}

; $L\ensuremath{\le}2$) and heteronuclear alkali-metal dimers in the ground rovibrational state ($X^{1}\mathrm{\ensuremath{\Sigma}}^{+}$;

v=0, J=0

). We compute the associated

{C}_{6}

dispersion coefficients of atom-molecule pairs involving

^{133}\mathrm{Cs}

and

^{85}\mathrm{Rb}

atoms interacting with KRb, LiCs, LiRb, and RbCs molecules. The obtained dispersion coefficients can be accurately fitted to a state-dependent polynomial

O({n}^{7})

over the range of principal quantum numbers $40\ensuremath{\le}n\ensuremath{\le}150$. For all atom-molecule pairs considered, Rydberg states

n^{2}S_{j}

and

n^{2}P_{j}

result in attractive

1/{R}^{6}

potentials. In contrast,

n^{2}D_{j}

states can give rise to repulsive potentials for specific atom-molecule pairs. The interaction energy at the LeRoy distance approximately scales as ${n}^{\ensuremath{-}5}$ for

n>40

. For intermediate values of $n\ensuremath{\lesssim}40$, both repulsive and attractive interaction energies of the order of 10--$1000\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\mathrm{K}$ can be achieved with specific atomic and molecular species. The accuracy of the reported

{C}_{6}

coefficients is limited by the quality of the atomic quantum defects, with relative errors $\mathrm{\ensuremath{\Delta}}{C}_{6}/{C}_{6}$ estimated to be no greater than 1% on average.