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

Optics and Spectroscopy

Observation of Quantum Beats of Two-Photon-Excited States of Xe upon Photoionization

E. A. Viktorov, A. A. Pastor, Pavel Yu. Serdobintsev, Nikolai N. Bezuglov

Published Dec 1, 2021• 4 citations
Publisher

Abstract

Abstract Ionization of coherently two-photon-excited superposition of 4f states of Xe in a supersonic atomic beam is studied by means of femtosecond pump–probe spectroscopy. Oscillatory structure in the photoionization signal is related to coherent beats of a superposition of excited states. High efficiency of the proposed scheme of registration of quantum beats was achieved due to nearly 100% efficiency of collecting photoelectrons, in contrast to detection of fluorescence used traditionally.

DOI
10.1134/s0030400x21090216

Related papers

Photoionization of polarized doublet states of Xenon atom

E. A. Viktorov, A. A. Pastor, Pavel Yu. Serdobintsev +2 more

Abstract We studied experimentally and theoretically the ionization of a two-photon excited superposition of 4f states of Xe atom by probe femtosecond pulse laser in a supersonic beam. The revealed oscillation structure in the observed photoionization signals is associated with the interference of the coherently populated components of Xe doublet states. Our results demonstrate the high efficiency of proposed experimental scheme for registering quantum beats in the photoelectron current.

Journal of Physics Conference Series•Dec 1, 2021•4 citations

Oscillations of photocurrent signals upon photoionization of polarized Ar and Xe atoms in magnetic fields

E. A. Viktorov, K. Miculis, Alexander Pastor +2 more

Ionization of polarized states of Ar and Xe atoms by femtosecond probe pulse in a supersonic beam in the presence of magnetic field was studied theoretically and experimentally. The revealed oscillation structure in the photoionization signals occurs due to the Larmor precession of exited atomic states in a magnetic field. We derived analytical formulas for the photoelectron current and explained the detected oscillations in terms of photon and atomic polarization moments. Our results indicate the possibility of implementing Doppler-free spectroscopy involving bound-free transitions.

•Apr 14, 2021•2 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

Modulation of quantum beats signal upon photoionization of Xe isotopes in the magnetic field

E. A. Viktorov, SERDOBINTSEV P.YU., Nikolai N. Bezuglov +1 more

Photoionization processes involving polarized Xe atoms in the presence of an external magnetic field were analyzed in our previous studies. It was shown that the modulation of quantum beats in the observed electronic photo signals could not be explained by the Paschen-Back effect accounting for fine-structure levels only. In the current work, ionized Xe+ isotopes are used as the output channel of photoionization. By comparing the temporal partial signals in the mass spectra of the Xe+ isotopes, it was possible to explain the modulation of quantum beats in ion fluxes as a consequence of the presence of the hyperfine structure in the Zeeman components of the 129Xe and 131Xe isotopes. Keywords: quantum beats, hyperfine structure, Zeeman effect, two-photon excitation, femtosecond ionization, "pump-probe"-experiment.

Оптика и спектроскопия•Jan 1, 2022•0 citations

Anisotropy quantum beat in two-photon ionization of coherently excited hyperfine states of Na

Young Jong Lee, Sung Haeng Cho, Nam Joon Kim +1 more

A new method is proposed that utilizes the quantum beat of polarization anisotropy in two-photon ionization of atoms and molecules. It was shown that the frequency and the amplitude of the beating anisotropy contain information on, respectively, the hyperfine constants of the electronically excited state and the branching ratio of the photoionization channels leading to different photoelectron angular momentum states in the ionization continuum. The method was demonstrated for the case of the Na 3p P3/22 state by the time-resolved two-photon ionization with two pulses of parallel and perpendicular polarizations.

The Journal of Chemical Physics•Jul 8, 2001•3 citations

FEMTOSECOND QUANTUM BEATS IN OPTICAL TRANSMISSION-CORRELATION AND PUMP-PROBE MEASUREMENTS.

Masaharu Mitsunaga, Carson L. Tang

Recent femtosecond transmission-correlation measurements1 of large organic dye molecules revealed surprising details concerning the ultrafast relaxation dynamics of such dyes. Superposed on simple exponential decays, the observation of damped sinusoidal oscillations with a period of ~ 150 fs has been puzzling. We theoretically and numerically demonstrate that such oscillatory behavior could be due to quantum beats of closely spaced two levels, whose coherent superposition state is optically prepared and monitored by a pair of femtosecond pulses. Although studies of quantum beats have been developed in both fluorescence-type2 and nonfluorescence-type measurements, such as those based on photon echoes3 or polarization spectroscopy,4 this simple method gives a new approach to femtosecond time domain spectroscopy. The generalized perturbation theory5 of optical coherent transients is extended to the case of optical transmission-correlation or pump-probe-type experiments. The model used is a three-level system which has split levels in either the ground or optically excited states. Especially, if the ground state has sublevels, the system becomes quite similar to the case of coherent Raman beats. Both cases are shown to give quantum beats when the excitation pulses are short compared with the inverse sublevel splitting. The period and decay time of the damped sinusoid represent the separation energy and the dephasing time between the sublevels, respectively. Using third-order perturbation theory, the transmission-correlation signal STC(τ) as a function of the first-to-second pulse delay time Is derived for arbitrary-shaped excitation pulses and is given in the form of fourfold integrals with many terms.

Journal of the Optical Society of America B•Jan 1, 1987•0 citations
Abstract Ionization of coherently two-photon-excited superposition of 4f states of Xe in a supersonic atomic beam is studied by means of femtosecond pump–probe spectroscopy. Oscillatory structure in the photoionization signal is related to coherent beats of a superposition of excited states. High efficiency of the proposed scheme of registration of quantum beats was achieved due to nearly 100% efficiency of collecting photoelectrons, in contrast to detection of fluorescence used traditionally.
Ionization of polarized states of Ar and Xe atoms by femtosecond probe pulse in a supersonic beam in the presence of magnetic field was studied theoretically and experimentally. The revealed oscillation structure in the photoionization signals occurs due to the Larmor precession of exited atomic states in a magnetic field. We derived analytical formulas for the photoelectron current and explained the detected oscillations in terms of photon and atomic polarization moments. Our results indicate the possibility of implementing Doppler-free spectroscopy involving bound-free transitions.
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.
Photoionization processes involving polarized Xe atoms in the presence of an external magnetic field were analyzed in our previous studies. It was shown that the modulation of quantum beats in the observed electronic photo signals could not be explained by the Paschen-Back effect accounting for fine-structure levels only. In the current work, ionized Xe+ isotopes are used as the output channel of photoionization. By comparing the temporal partial signals in the mass spectra of the Xe+ isotopes, it was possible to explain the modulation of quantum beats in ion fluxes as a consequence of the presence of the hyperfine structure in the Zeeman components of the 129Xe and 131Xe isotopes. Keywords: quantum beats, hyperfine structure, Zeeman effect, two-photon excitation, femtosecond ionization, "pump-probe"-experiment.
A new method is proposed that utilizes the quantum beat of polarization anisotropy in two-photon ionization of atoms and molecules. It was shown that the frequency and the amplitude of the beating anisotropy contain information on, respectively, the hyperfine constants of the electronically excited state and the branching ratio of the photoionization channels leading to different photoelectron angular momentum states in the ionization continuum. The method was demonstrated for the case of the Na 3p P3/22 state by the time-resolved two-photon ionization with two pulses of parallel and perpendicular polarizations.
Recent femtosecond transmission-correlation measurements1 of large organic dye molecules revealed surprising details concerning the ultrafast relaxation dynamics of such dyes. Superposed on simple exponential decays, the observation of damped sinusoidal oscillations with a period of ~ 150 fs has been puzzling. We theoretically and numerically demonstrate that such oscillatory behavior could be due to quantum beats of closely spaced two levels, whose coherent superposition state is optically prepared and monitored by a pair of femtosecond pulses. Although studies of quantum beats have been developed in both fluorescence-type2 and nonfluorescence-type measurements, such as those based on photon echoes3 or polarization spectroscopy,4 this simple method gives a new approach to femtosecond time domain spectroscopy. The generalized perturbation theory5 of optical coherent transients is extended to the case of optical transmission-correlation or pump-probe-type experiments. The model used is a three-level system which has split levels in either the ground or optically excited states. Especially, if the ground state has sublevels, the system becomes quite similar to the case of coherent Raman beats. Both cases are shown to give quantum beats when the excitation pulses are short compared with the inverse sublevel splitting. The period and decay time of the damped sinusoid represent the separation energy and the dephasing time between the sublevels, respectively. Using third-order perturbation theory, the transmission-correlation signal STC(τ) as a function of the first-to-second pulse delay time Is derived for arbitrary-shaped excitation pulses and is given in the form of fourfold integrals with many terms.