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Title: Motion in an ultralong-range potential in cold-Rydberg-atom collisions

Abstract

In a recent letter Li et al. [Phys. Rev. Lett. 94, 173001 (2005)] have studied experimentally the role of dipole-dipole interactions in the ionization of Rydberg atoms and the formation of a cold plasma. The authors associated their observations with atomic motion due to such interaction. In this work, we adapt the dynamical model proposed by De Oliveira et al. [Phys. Rev. Lett. 90, 143002 (2003)] based on a two atom interaction, which reproduce qualitatively well some experimental results observed by Li and co-workers. This comparison presents clear evidences of motion in such ultralong range potential between cold-Rydberg atoms, which may be important for some applications, as quantum computation.

Authors:
; ; ; ;  [1]
  1. Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Caixa Postal 369, 13560-970, Sao Carlos-SP (Brazil)
Publication Date:
OSTI Identifier:
20787017
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 73; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevA.73.034703; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; ATOM COLLISIONS; ATOMS; COLD PLASMA; COMPARATIVE EVALUATIONS; DIPOLES; POTENTIAL ENERGY; POTENTIALS; QUANTUM COMPUTERS; RYDBERG STATES

Citation Formats

Nascimento, V. A., Reetz-Lamour, M., Caliri, L. L., Oliveira, A. L. de, and Marcassa, L. G. Motion in an ultralong-range potential in cold-Rydberg-atom collisions. United States: N. p., 2006. Web. doi:10.1103/PHYSREVA.73.0.
Nascimento, V. A., Reetz-Lamour, M., Caliri, L. L., Oliveira, A. L. de, & Marcassa, L. G. Motion in an ultralong-range potential in cold-Rydberg-atom collisions. United States. doi:10.1103/PHYSREVA.73.0.
Nascimento, V. A., Reetz-Lamour, M., Caliri, L. L., Oliveira, A. L. de, and Marcassa, L. G. Wed . "Motion in an ultralong-range potential in cold-Rydberg-atom collisions". United States. doi:10.1103/PHYSREVA.73.0.
@article{osti_20787017,
title = {Motion in an ultralong-range potential in cold-Rydberg-atom collisions},
author = {Nascimento, V. A. and Reetz-Lamour, M. and Caliri, L. L. and Oliveira, A. L. de and Marcassa, L. G.},
abstractNote = {In a recent letter Li et al. [Phys. Rev. Lett. 94, 173001 (2005)] have studied experimentally the role of dipole-dipole interactions in the ionization of Rydberg atoms and the formation of a cold plasma. The authors associated their observations with atomic motion due to such interaction. In this work, we adapt the dynamical model proposed by De Oliveira et al. [Phys. Rev. Lett. 90, 143002 (2003)] based on a two atom interaction, which reproduce qualitatively well some experimental results observed by Li and co-workers. This comparison presents clear evidences of motion in such ultralong range potential between cold-Rydberg atoms, which may be important for some applications, as quantum computation.},
doi = {10.1103/PHYSREVA.73.0},
journal = {Physical Review. A},
number = 3,
volume = 73,
place = {United States},
year = {Wed Mar 15 00:00:00 EST 2006},
month = {Wed Mar 15 00:00:00 EST 2006}
}
  • 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.
  • Preliminary results of calculating the broadening of spectral lines of excited atoms induced by ultralong- range (100 Bohr radii) interactions in a cold gas of Rb atoms within the 'own pressure' approximation and perturbation theory formalism are presented.
  • In a previous Letter by Oliveira et al. [Phys. Rev. Lett. 90, 143002 (2003)], the time evolution of the 34S{sub 1/2} population, resulting from energy-transfer collisions between 33P{sub 3/2}+33P{sub 3/2} Rb atoms in a magneto-optical trap, was explained based on an ultralong-range potential. However, some experimental oscillations observed in the signal could not be reproduced by that model. In this work we reanalyze such a experimental results considering an internuclear separation-dependent colliding atomic pair distribution. This analysis suggests that such a distribution in the ultralong-range Rydberg molecular potential is responsible for the observed oscillations.
  • The experimental investigation of the resonant collision process Nans+Nans..-->..Nanp+Na(n-1)p which occurs when the levels are tuned with an electric field so that the ns level lies midway between the two p levels is described in detail. The observations are shown to be in good agreement with a long-range resonant dipole-dipole interaction.
  • The process of ionization in slow-atom--Rydberg-atom collisions is investigated. A resonant energy exchange mechanism is considered responsible for the electron transition into the continuum. Both symmetrical and asymmetrical systems are considered. The ionization probabilities and cross sections for a number of Rydberg states in the colliding systems H* (n)+H, Li* (n)+Li, H* (n)+Li are calculated.