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

Collisions of helium with Rydberg atoms in the presence of static electric and magnetic fields

Saverio Bivona, R. Burlon, G. Ferrante, C. Leone

Published Oct 22, 2004• 2 citations
Publisher

Abstract

Alignment and orientation effects in collisions of helium with Rydberg atoms due to the presence of static electric and magnetic fields are predicted. Analytical expressions are obtained for the cross sections of the state-to-state transitions within the manifold with the same principal quantum number. For moderate field-induced inelasticity, the curves of the cross sections vs the fields intensity show modulations that are explained in terms of the phase differences accumulated by the wave functions of the states involved in the collision. Due to the presence of the magnetic field, transitions involving inversion of high magnetic quantum numbers are dramatically quenched. The possibility of observing the predicted effects is discussed. The reported analytical cross sections are expected to help in the understanding of the results.

DOI
10.1103/physreva.70.042715

Related papers

Probing Rydberg atoms through collisions with helium in the presence of static electric and magnetic fields

Saverio Bivona, R. Burlon, G. Ferrante +1 more

We report on field induced inelasticity effects in state-to-state transitions caused by collisions of helium with Rydberg atoms in the presence of parallel static electric and magnetic fields. Due to the phases accumulated by the wavefunctions of the states involved into the collision events, the transition cross sections plotted as a function of the external fields exhibit modulations. When the relative velocity of the colliding atoms is high enough, these modulations are wiped out, while sizable modifications of the cross sections may take place due to the alteration of the wavefunctions' spatial localization. The possibility of using the field-assisted collisions as a probe giving information on localization of the Rydberg states is discussed.

Journal of Physics B Atomic Molecular and Optical Physics•Jan 6, 2005•4 citations

Collisions of Rydberg atoms in an electric field: Calculations using hydrogenic wave functions in parabolic coordinates

A. P. Hickman

The theory of collisions of Rydberg atoms with rare-gas atoms is generalized to include the effects of an applied static electric field. Two effects occur. First, the field causes the states to split, and the increased energy separations lead to a decrease in the inelastic cross sections. Second, there is a change in the form of the wave functions, because the various Stark states in the field have electron charge distributions that may be localized in very different regions of space. The present work focuses on this second effect. With the description of the initial and final Stark states of the Rydberg atom by the proper electronic wave functions obtained in parabolic coordinates, cross sections are obtained for a variety of specific transitions of Rydberg atoms ($n=10, 15, \mathrm{and} 20$) caused by collisions. The calculations are strictly valid for hydrogen, but exhibit general features that are expected to apply to other Rydberg atoms as well. The results show a dramatic effect on the cross section for particular transitions depending on the degree of overlap of the initial and final charge distributions. In addition, it is observed that transitions are favored that involve small changes in the azimuthal quantum number $m$. The origin of this tendency is discussed.

Physical Review A•Jul 1, 1983•18 citations

Influence of an external electric field on thermal collisions between ‘‘circular’’ Rydberg-state atoms and ground-state helium

E. de Prunelé

The influence of an external electric field on thermal collisions between a sodium atom excited in a ``circular'' Rydberg state (n=l+1=m+1=20) and a ground-state helium atom is studied numerically within the framework of the impulse approximation. The effect of the field is determined by using parabolic wave functions for the initial and final hydrogenic atomic states. The removal of degeneracy induced by the field appears to have no significant effect for fields in the range of 0--400 V/cm. However, the state-to-state transition cross sections are strongly dependent on the initial orientation as found in previous calculations without electric field.

Physical Review A•May 1, 1986•4 citations

Orientation effects in thermal collisions between ‘‘circular’’–Rydberg-state atoms and ground-state helium

E. de Prunelé

A general formulation for thermal collisions between a Rydberg-state atom and a ground-state rare-gas atom is developed within the framework of the impulse approximation. This formulation allows calculation of cross sections for state-to-state transitions for an arbitrary initial orientation between the Rydberg-state atom and the relative velocity of the two partners of the collision. It also allows a direct computation of these cross sections averaged over all orientations, a situation corresponding to a cell experiment. In this formulation, the differential cross sections with respect to the modulus of the momentum transfer are obtained analytically in terms of rotation matrix elements. Numerical applications are made for the case of a sodium atom in a ``circular'' Rydberg state (\ensuremath{\Vert}n,l,m〉, with l=m=n-1) colliding with helium. The collisional processes are found to be highly anisotropic. In particular, a selection rule may appear, or disappear, depending upon the initial orientation. The extension to the case where an external electric field is present is also discussed, with special emphasis on symmetry properties.

Physical Review A•Jun 1, 1985•16 citations

Alignment and geometrical effects on Stueckelberg interference structure in cross sections for inelastic collisions involving Rydberg atoms

Bidhan C. Saha, Neal F. Lane

A theoretical study of Stueckelberg interference structure in inelastic, state-changing integrated cross sections for collisions of low-Rydberg Na (n10) atoms with ground state He atoms is reported. The dependence of the Stueckelberg interference structure on orbital geometry and alignment of the initial state is predicted. Interference oscillations are found in the cross sections for both initial ns and np states; in the latter case, the features show considerable sensitivity with respect to variations in the spatial alignment of the principal axis of the electron charge distribution at some collision velocities and near isotropy at others.

Physical Review Letters•May 30, 1994•12 citations

Helium Rydberg states in parallel electric and magnetic fields

Tony van der Veldt, W. Vassen, W. Hogervorst

The n=60, L z =0 angular momentum manifold in helium is studied in the presence of an electric field parallel to a fixed magnetic field (B=0.1539 T). Results obtained from a CW laser-atomic beam experiment are compared with diagonalization calculations and with a WKB approximation including core effects. Core-induced anticrossings have been analysed in detail. The supersymmetry, including quasi-crossings in hydrogen to occur at the same value of the electric field strength, does not apply for L z =0 manifolds in non-hydrogenic Rydberg atoms.

Journal of Physics B Atomic Molecular and Optical Physics•Jul 14, 1993•12 citations
Alignment and orientation effects in collisions of helium with Rydberg atoms due to the presence of static electric and magnetic fields are predicted. Analytical expressions are obtained for the cross sections of the state-to-state transitions within the manifold with the same principal quantum number. For moderate field-induced inelasticity, the curves of the cross sections vs the fields intensity show modulations that are explained in terms of the phase differences accumulated by the wave functions of the states involved in the collision. Due to the presence of the magnetic field, transitions involving inversion of high magnetic quantum numbers are dramatically quenched. The possibility of observing the predicted effects is discussed. The reported analytical cross sections are expected to help in the understanding of the results.
We report on field induced inelasticity effects in state-to-state transitions caused by collisions of helium with Rydberg atoms in the presence of parallel static electric and magnetic fields. Due to the phases accumulated by the wavefunctions of the states involved into the collision events, the transition cross sections plotted as a function of the external fields exhibit modulations. When the relative velocity of the colliding atoms is high enough, these modulations are wiped out, while sizable modifications of the cross sections may take place due to the alteration of the wavefunctions' spatial localization. The possibility of using the field-assisted collisions as a probe giving information on localization of the Rydberg states is discussed.
The theory of collisions of Rydberg atoms with rare-gas atoms is generalized to include the effects of an applied static electric field. Two effects occur. First, the field causes the states to split, and the increased energy separations lead to a decrease in the inelastic cross sections. Second, there is a change in the form of the wave functions, because the various Stark states in the field have electron charge distributions that may be localized in very different regions of space. The present work focuses on this second effect. With the description of the initial and final Stark states of the Rydberg atom by the proper electronic wave functions obtained in parabolic coordinates, cross sections are obtained for a variety of specific transitions of Rydberg atoms (n=10,15,and20n=10, 15, \mathrm{and} 20n=10,15,and20) caused by collisions. The calculations are strictly valid for hydrogen, but exhibit general features that are expected to apply to other Rydberg atoms as well. The results show a dramatic effect on the cross section for particular transitions depending on the degree of overlap of the initial and final charge distributions. In addition, it is observed that transitions are favored that involve small changes in the azimuthal quantum number mmm. The origin of this tendency is discussed.
The influence of an external electric field on thermal collisions between a sodium atom excited in a ``circular'' Rydberg state (n=l+1=m+1=20) and a ground-state helium atom is studied numerically within the framework of the impulse approximation. The effect of the field is determined by using parabolic wave functions for the initial and final hydrogenic atomic states. The removal of degeneracy induced by the field appears to have no significant effect for fields in the range of 0--400 V/cm. However, the state-to-state transition cross sections are strongly dependent on the initial orientation as found in previous calculations without electric field.
A general formulation for thermal collisions between a Rydberg-state atom and a ground-state rare-gas atom is developed within the framework of the impulse approximation. This formulation allows calculation of cross sections for state-to-state transitions for an arbitrary initial orientation between the Rydberg-state atom and the relative velocity of the two partners of the collision. It also allows a direct computation of these cross sections averaged over all orientations, a situation corresponding to a cell experiment. In this formulation, the differential cross sections with respect to the modulus of the momentum transfer are obtained analytically in terms of rotation matrix elements. Numerical applications are made for the case of a sodium atom in a ``circular'' Rydberg state (\ensuremath{\Vert}n,l,m〉, with l=m=n-1) colliding with helium. The collisional processes are found to be highly anisotropic. In particular, a selection rule may appear, or disappear, depending upon the initial orientation. The extension to the case where an external electric field is present is also discussed, with special emphasis on symmetry properties.
A theoretical study of Stueckelberg interference structure in inelastic, state-changing integrated cross sections for collisions of low-Rydberg Na (n10) atoms with ground state He atoms is reported. The dependence of the Stueckelberg interference structure on orbital geometry and alignment of the initial state is predicted. Interference oscillations are found in the cross sections for both initial ns and np states; in the latter case, the features show considerable sensitivity with respect to variations in the spatial alignment of the principal axis of the electron charge distribution at some collision velocities and near isotropy at others.
The n=60, L z =0 angular momentum manifold in helium is studied in the presence of an electric field parallel to a fixed magnetic field (B=0.1539 T). Results obtained from a CW laser-atomic beam experiment are compared with diagonalization calculations and with a WKB approximation including core effects. Core-induced anticrossings have been analysed in detail. The supersymmetry, including quasi-crossings in hydrogen to occur at the same value of the electric field strength, does not apply for L z =0 manifolds in non-hydrogenic Rydberg atoms.