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

Application of associative ionization to the observation of quantum beats in low-lying atomic resonances

James F. Christian, Lavina C. Snoek, Simon G. Clement, Wim J. van der Zande

Published Mar 1, 1996• 15 citations
Publisher

Abstract

A method is described which allows the detection of atomic quantum beats or wave-packet evolution in low-lying states, phenomena which are usually difficult to observe. The excitation method consists of a phase-sensitive two-pulse technique. Detection of the excited-state population after the two pulses is achieved by monitoring rubidium dimer ions which are formed in the associative ionization reaction, Rb*(n)p+Rb \ensuremath{\rightarrow}${\mathrm{Rb}}_{2}^{+}$+${\mathit{e}}^{\mathrm{\ensuremath{-}}}$. The dimer ion yield as a function of the wavelength showed strong features, which coincided with the 8p to 15p atomic resonances. The two-pulse technique revealed atomic fine-structure quantum beats due to the coherent excitation of the ${\mathit{np}}^{2}$${\mathit{P}}_{1/2,3/2}$ fine-structure states of the atom. \textcopyright{} 1996 The American Physical Society.

DOI
10.1103/physreva.53.1894

Related papers

Interaction of atomic wave packets with four-wave mixing:?detection of rubidium and potassium wave packets by coherent ultraviolet emission

Henry Tran, P. C. John, Ju Gao +1 more

The observation of an atomic wave packet by use of a coherent, nonlinear-optical process is reported. Wave packets formed in K or Rb vapor by two-photon excitation of ns and (n-2)dstates (n=8 for K; n=11 , 12 for Rb) with red (~620-nm) , 80-100-fs pulses were detected by four-wave mixing in pump-probe experiments. The temporal behavior of the wave packet is observed by monitoring the coherent UV radiation generated near the alkali mp(2)P? (2)S(1/2) (7</=m</=12 for Rb; 5</=m</=7 for K) resonance transitions when a probe pulse is scattered by the wave packet established by the earlier (identical) pump pulse. The spatial and spectral characteristics of the UV emission are well described by axially phase-matched four-wave mixing, and all the prominent frequency components of the wave packets are associated with energy differences between pairs of excited states for which Diota=0 or Diota=2 . These results demonstrate that the wave packet modulates chi((3))of the medium, thus rendering the wave packet detectable.

Optics Letters•Jan 1, 1998•26 citations

Investigation of fine-structure quantum beats in sodium Rydberg atoms by field ionization

THOMAS H. JEYS, K. A. Smith, F. B. Dunning +1 more

Pulsed dye lasers are used to excite sodium atoms into a coherent superposition of high Rydberg $\mathrm{nd} (^{2}\mathrm{D}_{\frac{3}{2}},^{2}D_{\frac{5}{2}})$ states. Analysis of the field ionization behavior of these atoms reveals the time evolution of the superposition state. Rapid application of a weak electric field projects different components of the superposition state onto states having identifiably different field ionization behavior. Analysis of the signal from subsequent field ionization as a function of the time of weak-field application reveals fine-structure quantum beats. These beats result from the time development of the original superposition state. Measurements of the fine-structure quantum beat frequency are presented for the principal quantum numbers $n=32, 34, 35, 36, 38, \mathrm{and} 40$.

Physical Review A•Jun 1, 1981•31 citations

Quantum beats in photoionization from a coherent superposition of fine-structure levels

A. T. Georges, P. Lambropoulos

We present a theory of quantum beats in photoionization from a coherent superposition of ${D}_{\frac{3}{2},5.2}$ levels in alkali-metal atoms. The semiclassical density-matrix formalism is used to describe both the excitation of the ${D}_{\frac{3}{2},\frac{5}{2}}$ levels by a two-photon resonant pulse and the subsequent photoionization by a delayed probe pulse. Quantum beats occur in the ionization signal as a function of the delay of the probe pulse. The depth of modulation is determined for different light polarizations.

Physical Review A•Sep 1, 1978•35 citations

Dynamics of Interfering Wave Packets in Rubidium by High Resolution Quantum Beat Spectroscopy

William Goldshlag

High resolution quantum beat spectroscopy has been realized to study atomic wave packet dynamics. Wave packets comprising pairs of low quantum number (n = 5 - 8) electronic states were formed in Rb vapor with ultrafast laser pulses, and their dynamics was observed by an all-optical technique of parametric four wave mixing (PFWM). The experimental apparatus designed, constructed and automated for this work provided unprecedented signal intensity that enabled time-frequency-resolved analysis of wave packet dynamics with picosecond temporal resolution over the course of 1100 ps. Both time-resolved and non-time-resolved discrete Fourier methods were applied to measure the concurrent formation of multiple wave packets. Many novel effects and interactions have been measured either for the first time or with greatly improved signal-to-noise ratio. Among them were the formation of the 8S1/2 - 6D5/2 wave packet that was not directly excited by the ultrafast radiation, formation and relative dynamics of quantum beating harmonics up to 73 THz, and quantum beating revivals. The effects of vapor number density and temperature were analyzed experimentally. Interference between the 7S1/2 - 5D5/2 and 8S1/2 - 6D5/2 wave packets (frequencies of 18.225 THz and 10.73 THz, respectively) has been observed for the first time and will be described in detail.

•Dec 8, 2017•0 citations

High-resolution spectroscopy based on atomic coherences

Alan Corney

Abstract The paper surveys the techniques of Doppler-free spectroscopy based on the creation and detection of Hertzian coherence in atomic and molecular systems. The preparation of individual atoms in a coherent superposition of states with the use of broadband optical excitation is discussed, with particular reference to excitation by pulsed tunable dye lasers. Time-resolved observations of the fluorescent light emitted by these atoms reveal the interference phenomenon known as quantum beats and enable Landé g-factors, fine and hyperfine splittings of excited levels to be determined. An account of progress in recent experiments with probe-beam monitoring and pulse trains from mode-locked dye lasers completes this review.

Philosophical Transactions of the Royal Society of London Series A Mathematical and Physical Sciences•Nov 12, 1982•3 citations

Study of wavepacket dynamics in rubidium vapor by means of time-frequency analysis

Andrey A. Senin

Wavepackets are excited in rubidium vapor by intense ultrashort (∼100 fs) pulses centered at a wavelength of 620 nm or 770 nm. The generated atomic wavepackets are optically detected via a pump-probe experiment based on axially phase-matched parametric four-wave mixing (FWM). This nonlinear process results in coherent ultraviolet (UV) or violet emission that carries information about the relative number densities of the excited states. The frequency spectrum of the UV/violet signal intensity, recorded while varying the pump-probe time delay, shows the presence of quantum beats between energy levels involved in the FWM process. The time-frequency analysis of that temporal UV/violet data is done by means of the short-time Fourier transform that leads to retrieval of the temporal evolution of amplitude and phase of the quantum beats. The observed dynamics suggest that not only atomic but also molecular ( Rb*2 ) wavepackets are generated, and that the temporal history of the amplitude of the quantum beats reflects the production of the excited atomic fragments of Rb*2 dissociation. More precisely, changes in the Rb excited state number densities alter the third-order nonlinear susceptibility chi(3) of the Rb vapor, which affects generation of the output signal wave by FWM. Dissociation into several product states is detected, and their branching ratios are estimated. Thus, atomic wavepackets, combined with FWM, appear to be a sensitive new multichannel spectroscopic means to study the fundamental process of molecular dissociation.

•Jan 1, 2003•0 citations
A method is described which allows the detection of atomic quantum beats or wave-packet evolution in low-lying states, phenomena which are usually difficult to observe. The excitation method consists of a phase-sensitive two-pulse technique. Detection of the excited-state population after the two pulses is achieved by monitoring rubidium dimer ions which are formed in the associative ionization reaction, Rb*(n)p+Rb \ensuremath{\rightarrow}Rb2+{\mathrm{Rb}}_{2}^{+}Rb2+​+e\ensuremath−{\mathit{e}}^{\mathrm{\ensuremath{-}}}e\ensuremath−. The dimer ion yield as a function of the wavelength showed strong features, which coincided with the 8p to 15p atomic resonances. The two-pulse technique revealed atomic fine-structure quantum beats due to the coherent excitation of the {\mathit{np}}^{2}$${\mathit{P}}_{1/2,3/2} fine-structure states of the atom. \textcopyright{} 1996 The American Physical Society.
The observation of an atomic wave packet by use of a coherent, nonlinear-optical process is reported. Wave packets formed in K or Rb vapor by two-photon excitation of ns and (n-2)dstates (n=8 for K; n=11 , 12 for Rb) with red (~620-nm) , 80-100-fs pulses were detected by four-wave mixing in pump-probe experiments. The temporal behavior of the wave packet is observed by monitoring the coherent UV radiation generated near the alkali mp(2)P? (2)S(1/2) (7</=m</=12 for Rb; 5</=m</=7 for K) resonance transitions when a probe pulse is scattered by the wave packet established by the earlier (identical) pump pulse. The spatial and spectral characteristics of the UV emission are well described by axially phase-matched four-wave mixing, and all the prominent frequency components of the wave packets are associated with energy differences between pairs of excited states for which Diota=0 or Diota=2 . These results demonstrate that the wave packet modulates chi((3))of the medium, thus rendering the wave packet detectable.
Pulsed dye lasers are used to excite sodium atoms into a coherent superposition of high Rydberg nd(2D32,2D52)\mathrm{nd} (^{2}\mathrm{D}_{\frac{3}{2}},^{2}D_{\frac{5}{2}})nd(2D23​​,2D25​​) states. Analysis of the field ionization behavior of these atoms reveals the time evolution of the superposition state. Rapid application of a weak electric field projects different components of the superposition state onto states having identifiably different field ionization behavior. Analysis of the signal from subsequent field ionization as a function of the time of weak-field application reveals fine-structure quantum beats. These beats result from the time development of the original superposition state. Measurements of the fine-structure quantum beat frequency are presented for the principal quantum numbers n=32,34,35,36,38,and40n=32, 34, 35, 36, 38, \mathrm{and} 40n=32,34,35,36,38,and40.
We present a theory of quantum beats in photoionization from a coherent superposition of D32,5.2{D}_{\frac{3}{2},5.2}D23​,5.2​ levels in alkali-metal atoms. The semiclassical density-matrix formalism is used to describe both the excitation of the D32,52{D}_{\frac{3}{2},\frac{5}{2}}D23​,25​​ levels by a two-photon resonant pulse and the subsequent photoionization by a delayed probe pulse. Quantum beats occur in the ionization signal as a function of the delay of the probe pulse. The depth of modulation is determined for different light polarizations.
High resolution quantum beat spectroscopy has been realized to study atomic wave packet dynamics. Wave packets comprising pairs of low quantum number (n = 5 - 8) electronic states were formed in Rb vapor with ultrafast laser pulses, and their dynamics was observed by an all-optical technique of parametric four wave mixing (PFWM). The experimental apparatus designed, constructed and automated for this work provided unprecedented signal intensity that enabled time-frequency-resolved analysis of wave packet dynamics with picosecond temporal resolution over the course of 1100 ps. Both time-resolved and non-time-resolved discrete Fourier methods were applied to measure the concurrent formation of multiple wave packets. Many novel effects and interactions have been measured either for the first time or with greatly improved signal-to-noise ratio. Among them were the formation of the 8S1/2 - 6D5/2 wave packet that was not directly excited by the ultrafast radiation, formation and relative dynamics of quantum beating harmonics up to 73 THz, and quantum beating revivals. The effects of vapor number density and temperature were analyzed experimentally. Interference between the 7S1/2 - 5D5/2 and 8S1/2 - 6D5/2 wave packets (frequencies of 18.225 THz and 10.73 THz, respectively) has been observed for the first time and will be described in detail.
Abstract The paper surveys the techniques of Doppler-free spectroscopy based on the creation and detection of Hertzian coherence in atomic and molecular systems. The preparation of individual atoms in a coherent superposition of states with the use of broadband optical excitation is discussed, with particular reference to excitation by pulsed tunable dye lasers. Time-resolved observations of the fluorescent light emitted by these atoms reveal the interference phenomenon known as quantum beats and enable Landé g-factors, fine and hyperfine splittings of excited levels to be determined. An account of progress in recent experiments with probe-beam monitoring and pulse trains from mode-locked dye lasers completes this review.
Wavepackets are excited in rubidium vapor by intense ultrashort (∼100 fs) pulses centered at a wavelength of 620 nm or 770 nm. The generated atomic wavepackets are optically detected via a pump-probe experiment based on axially phase-matched parametric four-wave mixing (FWM). This nonlinear process results in coherent ultraviolet (UV) or violet emission that carries information about the relative number densities of the excited states. The frequency spectrum of the UV/violet signal intensity, recorded while varying the pump-probe time delay, shows the presence of quantum beats between energy levels involved in the FWM process. The time-frequency analysis of that temporal UV/violet data is done by means of the short-time Fourier transform that leads to retrieval of the temporal evolution of amplitude and phase of the quantum beats. The observed dynamics suggest that not only atomic but also molecular ( Rb*2 ) wavepackets are generated, and that the temporal history of the amplitude of the quantum beats reflects the production of the excited atomic fragments of Rb*2 dissociation. More precisely, changes in the Rb excited state number densities alter the third-order nonlinear susceptibility chi(3) of the Rb vapor, which affects generation of the output signal wave by FWM. Dissociation into several product states is detected, and their branching ratios are estimated. Thus, atomic wavepackets, combined with FWM, appear to be a sensitive new multichannel spectroscopic means to study the fundamental process of molecular dissociation.