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

Physical Review A

Augmented long-range attraction in collisions involving a Rydberg atom

Charles E. Burkhardt, M. Ciocca, Jacob J. Leventhal, J. D. Kelley

Published Nov 1, 1992• 2 citations
Publisher

Abstract

The mechanism of reactive processes in binary atomic encounters is investigated by employing a Rydberg atom as one of the reactants. This permits isolation of the excited valence electron so that its role in effecting the heavy-body process can be assessed. Penning ionization by a Rydberg atom, which is studied as an example of a reactive process, is shown to have a cross section significantly higher than might be inferred solely on the basis of overlap of the atomic wave functions of the ionic Rydberg core and the collision partner. A model to describe these reactive processes in which the nearly isolated Rydberg electron polarizes, and is therefore attracted by, the neutral ground-state reactant is proposed. This attraction occurs at an internuclear separation greater than that at which the ionic core of the Rydberg atom can substantially polarize the neutral atom but polarization of the neutral atom by the Rydberg electron leads to a transitory negative ion and concomitant Coulomb attraction to the ionic core. This Coulomb attraction thus leads to cross sections that are higher than would be calculated solely on the basis of atomic overlap.

DOI
10.1103/physreva.46.5795

Related papers

Collisions of Rydberg atoms with neutral targets

F. B. Dunning, Sitti Buathong

Atoms in highly excited Rydberg states possess physical characteristics quite unlike those associated with atoms in the ground or low-lying excited states. In particular, they are physically very large and are only very weakly bound. In consequence, collisions can lead to a wide variety of reaction processes many of which are unique to Rydberg species and have very large collision cross sections. In collisions with neutral targets, Rydberg atoms behave not as an atom but rather as a pair of well-separated independent scatterers, namely the core ion and the excited Rydberg electron. In the present article we discuss many of the different reactions that can occur when Rydberg atoms collide with neutral targets, focusing principally on reactions that are dominated by (binary) Rydberg electron-target interactions and include collisions with molecules that attach free low-energy electrons and with polar targets. In certain situations, however, interactions involving the Rydberg core ion are important. This is illustrated using as an example the destruction of ultralong-range Rydberg molecules excited in a cold dense gas.

International Reviews in Physical Chemistry•Apr 3, 2018•5 citations

Collisions with neutral atoms and molecules

Thomas F. Gallagher

The large size and low binding energies, scaling as n 4 and n −2 , of Rydberg atoms make them nearly irresistible subjects for collision experiments. While one might expect collision cross sections to be enormous, by and large they are not. In fact, Rydberg atoms are quite transparent to most collision partners. Collisions involving Rydberg atoms can be broken into two general categories, collisions in which the collision partner, or perturber, interacts with the Rydberg atom as a whole, and those in which the perturber interacts separately with the ionic core and the Rydberg electron. The difference between these two categories is in essence a question of the range of the interaction between the perturber and the Rydberg atom relative to the size of the Rydberg atom. A few examples serve to clarify this point. A Rydberg atom interacting with a charged particle is a charge–dipole interaction with a 1/ R 2 interaction potential, and the resonant dipole–dipole interaction between two Rydberg atoms has a 1/ R 3 interaction potential. Here R is the internuclear separation of the Rydberg atom and the perturber. In both of these interactions the perturber interacts with the Rydberg atom as a whole. On the other hand when a Rydberg atom interacts with a N 2 molecule the longest range atom–molecule interaction is a dipole–induced dipole interaction with a potential varying as 1/ R 6 .

Cambridge University Press eBooks•Sep 15, 1994•0 citations

Role of the valence electron in reactive processes: Penning ionization by a Rydberg atom

Charles E. Burkhardt, M. Ciocca, Jacob J. Leventhal +1 more

We report results of ${\mathrm{Ba}}^{\mathrm{*}\mathrm{*}}$-Na Penning ionization experiments in which the reactivity of pure Rydberg states is compared with that of mixed Rydberg-valence states. Pure states having energy near the ionization threshold of Na are highly reactive, \ensuremath{\sigma}\ensuremath{\approxeq}2500 \AA{} $^{2}$ for Ba(17d $^{1}$${\mathit{D}}_{2}$), but mixed states are unreactive. These results are explained using a model that includes an ion-induced dipole ${\mathrm{Ba}}^{+}$-Na interaction and a modified Coulomb interaction resulting from fractional charge accumulation around the Na.

Physical Review Letters•Nov 5, 1990•4 citations

Transfer of a weakly bound electron in collisions of Rydberg atoms with neutral particles. I. Long-range interaction effects in the ionic-covalent coupling

Владимир Сергеевич Лебедев, Alexander A. Narits

Ion-pair formation processes are studied in collisions of Rydberg atoms with neutral particles possessing small electron affinities. Nonadiabatic transitions from a Rydberg covalent term to an ionic term of a quasi-molecule are considered using the modified Landau-Zener theory supplemented with calculation of survival factors of an anion decaying in the Coulomb field of a positive ion core. Using the technique of irreducible tensor operators and the momentum representation of the wavefunction of a highly excited atom, exact expressions are obtained for transition matrix elements and the ionic-covalent coupling parameter. The approach developed in the paper provides the description beyond the scope of a conventional assumption about a small variation of the wavefunction of the Rydberg atom on the range of electron coordinates determined by the characteristic radius of the wavefunction of the anion. This allows one to correctly consider long-range effects of the interaction between a weakly bound electron and the neutral core of a negative ion in processes under study. It is shown by the example of thermal collisions of Xe( nf ) atoms with CH 3 CN molecules that this is very important for a reliable quantitative description of anion formation with a low binding energy. The results are compared with experiments and calculations performed within the framework of a number of approximate methods.

Journal of Experimental and Theoretical Physics•Oct 1, 2013•6 citations

Theoretical studies of Rydberg atom collisions

R.E. Olson

During the last two years, theoretical studies were performed on a variety of topics related to collisions involving Rydberg atoms. Progress was made towards the understanding of ion-Rydberg atom, Rydberg atom-Rydberg atom, and ground state atom-Rydberg atom collisions. Cross sections were calculated for electron capture, ionization, and excitation processes and parametrized in terms of atomic parameters. A strong dc electric field was also incoporated in calculations of electron capture and ionization cross sections for ion-Rydberg atom collisions. The results of this latter investigation indicate the design of a far ir photon detector which is based on the field ionization of Rydberg atoms may be limited by the collision processes. (Author)

Final Report•Nov 28, 1984•0 citations

Resonant quenching of Rydberg atomic states by highly polar molecules

Alexander A. Narits, E. S. Mironchuk, Владимир Сергеевич Лебедев

Abstract The results of theoretical studies of the resonant quenching and ion-pair formation processes induced by collisions of Rydberg atoms with highly polar molecules possessing small electron affinities are reported. We elaborate an approach for describing collisional dynamics of both processes and demonstrate the predominant role of resonant quenching channel of reaction for the destruction of Rydberg states by electron-attaching molecules. The approach is based on the solution of the coupled differential equations for the transition amplitudes between the ionic and Rydberg covalent terms of a quasimolecule formed during a collision of particles. It takes into account the possibility of the dipole-bound anion decay in the Coulomb field of the positive ionic core and generalizes previous models of charge-transfer processes involving Rydberg atoms to the cases, when the multistate Landau–Zener approaches become inapplicable. Our calculations for Rb ( nl ) atom perturbed by C 2 H 4 SO 3 , CH 2 CHCN , CH 3 NO 2 , CH 3 CN , C 3 H 2 O 3 , and C 3 H 4 O 3 molecules show that the curves representing the dependence of the resonant quenching cross sections on the principal quantum number n are bell-shaped with the positions of maxima being shifted towards lower values of n and the peak values, σ max ( q ) , several times higher than those for the ion-pair formation, σ max

Journal of Physics B Atomic Molecular and Optical Physics•May 18, 2016•4 citations
The mechanism of reactive processes in binary atomic encounters is investigated by employing a Rydberg atom as one of the reactants. This permits isolation of the excited valence electron so that its role in effecting the heavy-body process can be assessed. Penning ionization by a Rydberg atom, which is studied as an example of a reactive process, is shown to have a cross section significantly higher than might be inferred solely on the basis of overlap of the atomic wave functions of the ionic Rydberg core and the collision partner. A model to describe these reactive processes in which the nearly isolated Rydberg electron polarizes, and is therefore attracted by, the neutral ground-state reactant is proposed. This attraction occurs at an internuclear separation greater than that at which the ionic core of the Rydberg atom can substantially polarize the neutral atom but polarization of the neutral atom by the Rydberg electron leads to a transitory negative ion and concomitant Coulomb attraction to the ionic core. This Coulomb attraction thus leads to cross sections that are higher than would be calculated solely on the basis of atomic overlap.
Atoms in highly excited Rydberg states possess physical characteristics quite unlike those associated with atoms in the ground or low-lying excited states. In particular, they are physically very large and are only very weakly bound. In consequence, collisions can lead to a wide variety of reaction processes many of which are unique to Rydberg species and have very large collision cross sections. In collisions with neutral targets, Rydberg atoms behave not as an atom but rather as a pair of well-separated independent scatterers, namely the core ion and the excited Rydberg electron. In the present article we discuss many of the different reactions that can occur when Rydberg atoms collide with neutral targets, focusing principally on reactions that are dominated by (binary) Rydberg electron-target interactions and include collisions with molecules that attach free low-energy electrons and with polar targets. In certain situations, however, interactions involving the Rydberg core ion are important. This is illustrated using as an example the destruction of ultralong-range Rydberg molecules excited in a cold dense gas.
The large size and low binding energies, scaling as n 4 and n −2 , of Rydberg atoms make them nearly irresistible subjects for collision experiments. While one might expect collision cross sections to be enormous, by and large they are not. In fact, Rydberg atoms are quite transparent to most collision partners. Collisions involving Rydberg atoms can be broken into two general categories, collisions in which the collision partner, or perturber, interacts with the Rydberg atom as a whole, and those in which the perturber interacts separately with the ionic core and the Rydberg electron. The difference between these two categories is in essence a question of the range of the interaction between the perturber and the Rydberg atom relative to the size of the Rydberg atom. A few examples serve to clarify this point. A Rydberg atom interacting with a charged particle is a charge–dipole interaction with a 1/ R 2 interaction potential, and the resonant dipole–dipole interaction between two Rydberg atoms has a 1/ R 3 interaction potential. Here R is the internuclear separation of the Rydberg atom and the perturber. In both of these interactions the perturber interacts with the Rydberg atom as a whole. On the other hand when a Rydberg atom interacts with a N 2 molecule the longest range atom–molecule interaction is a dipole–induced dipole interaction with a potential varying as 1/ R 6 .
We report results of Ba∗∗{\mathrm{Ba}}^{\mathrm{*}\mathrm{*}}Ba∗∗-Na Penning ionization experiments in which the reactivity of pure Rydberg states is compared with that of mixed Rydberg-valence states. Pure states having energy near the ionization threshold of Na are highly reactive, \ensuremath{\sigma}\ensuremath{\approxeq}2500 \AA{} 2^{2}2 for Ba(17d 1^{1}1D2{\mathit{D}}_{2}D2​), but mixed states are unreactive. These results are explained using a model that includes an ion-induced dipole Ba+{\mathrm{Ba}}^{+}Ba+-Na interaction and a modified Coulomb interaction resulting from fractional charge accumulation around the Na.
Ion-pair formation processes are studied in collisions of Rydberg atoms with neutral particles possessing small electron affinities. Nonadiabatic transitions from a Rydberg covalent term to an ionic term of a quasi-molecule are considered using the modified Landau-Zener theory supplemented with calculation of survival factors of an anion decaying in the Coulomb field of a positive ion core. Using the technique of irreducible tensor operators and the momentum representation of the wavefunction of a highly excited atom, exact expressions are obtained for transition matrix elements and the ionic-covalent coupling parameter. The approach developed in the paper provides the description beyond the scope of a conventional assumption about a small variation of the wavefunction of the Rydberg atom on the range of electron coordinates determined by the characteristic radius of the wavefunction of the anion. This allows one to correctly consider long-range effects of the interaction between a weakly bound electron and the neutral core of a negative ion in processes under study. It is shown by the example of thermal collisions of Xe( nf ) atoms with CH 3 CN molecules that this is very important for a reliable quantitative description of anion formation with a low binding energy. The results are compared with experiments and calculations performed within the framework of a number of approximate methods.
During the last two years, theoretical studies were performed on a variety of topics related to collisions involving Rydberg atoms. Progress was made towards the understanding of ion-Rydberg atom, Rydberg atom-Rydberg atom, and ground state atom-Rydberg atom collisions. Cross sections were calculated for electron capture, ionization, and excitation processes and parametrized in terms of atomic parameters. A strong dc electric field was also incoporated in calculations of electron capture and ionization cross sections for ion-Rydberg atom collisions. The results of this latter investigation indicate the design of a far ir photon detector which is based on the field ionization of Rydberg atoms may be limited by the collision processes. (Author)
Abstract The results of theoretical studies of the resonant quenching and ion-pair formation processes induced by collisions of Rydberg atoms with highly polar molecules possessing small electron affinities are reported. We elaborate an approach for describing collisional dynamics of both processes and demonstrate the predominant role of resonant quenching channel of reaction for the destruction of Rydberg states by electron-attaching molecules. The approach is based on the solution of the coupled differential equations for the transition amplitudes between the ionic and Rydberg covalent terms of a quasimolecule formed during a collision of particles. It takes into account the possibility of the dipole-bound anion decay in the Coulomb field of the positive ionic core and generalizes previous models of charge-transfer processes involving Rydberg atoms to the cases, when the multistate Landau–Zener approaches become inapplicable. Our calculations for Rb ( nl ) atom perturbed by C 2 H 4 SO 3 , CH 2 CHCN , CH 3 NO 2 , CH 3 CN , C 3 H 2 O 3 , and C 3 H 4 O 3 molecules show that the curves representing the dependence of the resonant quenching cross sections on the principal quantum number n are bell-shaped with the positions of maxima being shifted towards lower values of n and the peak values, σ max ( q ) , several times higher than those for the ion-pair formation, σ max