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

Population trapping in a multilevel system

PAUL M. RADMORE

Published Oct 1, 1982• 17 citations
Publisher

Abstract

In a two-photon resonant three-level system, population can be trapped in a noninteracting superposition state. We demonstrate that this phenomenon persists in a multilevel system in which the final state is replaced by a number of nondegenerate states. The magnitude of the trapped population depends only on the matrix elements between the pair of two-photon resonant levels and the intermediate level. A dressed-state approach is also considered.

DOI
10.1103/physreva.26.2252

Related papers

Population trapping and dispersion in a three-level system

PAUL M. RADMORE, P. L. Knight

The population dynamics and spectra of a three-level system driven by two applied fields of arbitrary amplitudes and detunings are examined using dressed-state techniques. The authors report the existence of novel dispersive features in the variation with detuning of the intermediate-state population.

Journal of Physics B Atomic and Molecular Physics•Feb 28, 1982•243 citations

Population trapping in a Raman-coupled model interacting with a two-mode quantized cavity field

Bimalendu Deb, Gautam Gangopadhyay, Deb Shankar Ray

We investigate the population trapping in a Raman-coupled three-level system interacting with a pump mode and a Stokes mode in a quantized cavity. We show that with an initial atom-field decoupled state and the atomic state prepared in a coherent superposition of two nondegenerate ground states, population trapping occurs when the phase of the atomic dipole is equal to the phase difference of the two modes and the two-mode field state satisfies a specific photon distribution. In the limit of large total photon number, under some specific conditions, the corresponding two-mode trapping state can be identified as a phase difference state. We have studied the variance of superposition mode quadrature and its evolution, statistical properties, and the phase-space properties of the two-mode trapping field state. It has been observed that although under different conditions the two-mode field exhibits both sub- and super-Poissonian statistics, no squeezing is observed in any case.

Physical Review A•Aug 1, 1993•21 citations

Population trapping in two-level models: Spectral and statistical properties

J. I. Cirac, Luis Lorenzo Sánchez-Soto

The interaction of a two-level atom with a single-mode radiation field through multiphoton transitions is studied in terms of the dressed-state formalism. It is shown that when only certain dressed states are initially excited, population trapping occurs. We particularize these results for some well-known models of one- and two-photon transitions. Photon statistics of the cavity mode is analyzed in terms of the quasiprobability distribution Q(\ensuremath{\alpha}). It is shown that when population trapping occurs some two-time correlation functions become stationary, which allows one to obtain the resonance spectrum as the Fourier transform of the two-time dipole autocorrelation function.

Physical Review A•Sep 1, 1991•28 citations

Coherent Population Trapping in Two-Electron Three-Level Systems with Aligned Spins

J. Mompart, R. Corbalán, L. Roso

The possibility of coherent population trapping in two electron states with aligned spins (orthosystem) is evidenced. From the analysis of a three-level atomic system containing two electrons, and driven by the two laser fields needed for coherent population trapping, a conceptually new kind of dark state appears. The properties of this trapping are physically interpreted in terms of a dark hole, instead of a dark two-electron state. This technique, among many other applications, offers the possibility of measuring, with subnatural resolution, some superposition-state matrix elements of the electron-electron correlation that due to their time dependent nature are inaccessible by standard measuring procedures.

arXiv:quant-ph/0107126•Physical Review Letters•Dec 21, 2001•16 citations

Squeezing and trapping in three-level atoms

F. A. M. de Oliveira, Bryan J. Dalton, P. L. Knight

We discuss the phase-sensitive noise properties of fluorescence emitted by three-level atoms coherently excited by two laser fields, using both undressed and dressed uncoupled-state representations. The occurrence of steady-state squeezing is found to be highly sensitive to relaxation processes between the two-photon resonant levels. For purely radiative decay from the upper level, and no lower-state relaxation, the population is susceptible to coherent population trapping. Near two-photon resonance, the atom is optically pumped into a nonabsorbing (trapped) superposition state, which, although it reduces upper-level population, also leads to an interference cancellation of dipole moments and to suppression of squeezing. Lower-level relaxation unbalances this interference and restores the squeezing to some extent. Transient squeezing is also predicted in the time-dependent fluorescence.

Journal of the Optical Society of America B•Oct 1, 1987•31 citations

Coherently pumped two-frequency laser-type devices

I. R. Senitzky

A three-level system which radiates at both intermediate transition frequencies is considered to be coherently pumped at a frequency near the two-photon resonance frequency. A sharply resonant rise in the second- and third-level population is found for slight detuning of the pump from two-photon resonance. Population inversion in either transition is shown to be possible, depending on the pertinent parameters. This effect furnishes a novel method of population inversion at a frequency higher than the pump frequency. Keywords include: Laser, Laser-type devices, Coherent pumping, Three-level systems, and Quantum electronics.

Final Technical Report•Feb 1, 1985•0 citations
In a two-photon resonant three-level system, population can be trapped in a noninteracting superposition state. We demonstrate that this phenomenon persists in a multilevel system in which the final state is replaced by a number of nondegenerate states. The magnitude of the trapped population depends only on the matrix elements between the pair of two-photon resonant levels and the intermediate level. A dressed-state approach is also considered.
We investigate the population trapping in a Raman-coupled three-level system interacting with a pump mode and a Stokes mode in a quantized cavity. We show that with an initial atom-field decoupled state and the atomic state prepared in a coherent superposition of two nondegenerate ground states, population trapping occurs when the phase of the atomic dipole is equal to the phase difference of the two modes and the two-mode field state satisfies a specific photon distribution. In the limit of large total photon number, under some specific conditions, the corresponding two-mode trapping state can be identified as a phase difference state. We have studied the variance of superposition mode quadrature and its evolution, statistical properties, and the phase-space properties of the two-mode trapping field state. It has been observed that although under different conditions the two-mode field exhibits both sub- and super-Poissonian statistics, no squeezing is observed in any case.
The interaction of a two-level atom with a single-mode radiation field through multiphoton transitions is studied in terms of the dressed-state formalism. It is shown that when only certain dressed states are initially excited, population trapping occurs. We particularize these results for some well-known models of one- and two-photon transitions. Photon statistics of the cavity mode is analyzed in terms of the quasiprobability distribution Q(\ensuremath{\alpha}). It is shown that when population trapping occurs some two-time correlation functions become stationary, which allows one to obtain the resonance spectrum as the Fourier transform of the two-time dipole autocorrelation function.
The possibility of coherent population trapping in two electron states with aligned spins (orthosystem) is evidenced. From the analysis of a three-level atomic system containing two electrons, and driven by the two laser fields needed for coherent population trapping, a conceptually new kind of dark state appears. The properties of this trapping are physically interpreted in terms of a dark hole, instead of a dark two-electron state. This technique, among many other applications, offers the possibility of measuring, with subnatural resolution, some superposition-state matrix elements of the electron-electron correlation that due to their time dependent nature are inaccessible by standard measuring procedures.
We discuss the phase-sensitive noise properties of fluorescence emitted by three-level atoms coherently excited by two laser fields, using both undressed and dressed uncoupled-state representations. The occurrence of steady-state squeezing is found to be highly sensitive to relaxation processes between the two-photon resonant levels. For purely radiative decay from the upper level, and no lower-state relaxation, the population is susceptible to coherent population trapping. Near two-photon resonance, the atom is optically pumped into a nonabsorbing (trapped) superposition state, which, although it reduces upper-level population, also leads to an interference cancellation of dipole moments and to suppression of squeezing. Lower-level relaxation unbalances this interference and restores the squeezing to some extent. Transient squeezing is also predicted in the time-dependent fluorescence.
A three-level system which radiates at both intermediate transition frequencies is considered to be coherently pumped at a frequency near the two-photon resonance frequency. A sharply resonant rise in the second- and third-level population is found for slight detuning of the pump from two-photon resonance. Population inversion in either transition is shown to be possible, depending on the pertinent parameters. This effect furnishes a novel method of population inversion at a frequency higher than the pump frequency. Keywords include: Laser, Laser-type devices, Coherent pumping, Three-level systems, and Quantum electronics.