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

Journal of Physics B Atomic and Molecular Physics

Superradiance fluctuations in a j=1/2to j'=1/2atomic system

A. Crubellier, Sylvain Liberman, P. Pillet

Published Jul 28, 1984• 11 citations
Publisher

Abstract

The authors report on an experimental study of intensity and delay fluctuations for a two-level system by analysing stochastic distribution of the polarisation of superradiant pulses emitted on the transition 6p 2 P 1 /2 to 6s 2 S 1/2 of rubidium atoms. They develop a theoretical interpretation of their results. Finally, use of these properties of polarisation fluctuations has permitted one to study the very beginning of the superradiant emission and to give a new estimate of the so-called 'tipping angle'.

DOI
10.1088/0022-3700/17/14/008

Related papers

Experimental study of quantum fluctuations of polarisation in superradiance

A. Crubellier, Sylvain Liberman, P. Pillet +1 more

The superradiant light emitted on the transition 6p2P1/2 to 6s2S1/2 of Rb I has been found to be roughly linearly polarised with a polarisation direction changing randomly from pulse to pulse. The stochastic distribution of the polarisation which provides evidence of the quantum fluctuations of a two-level system has been investigated.

Journal of Physics B Atomic and Molecular Physics•Mar 14, 1981•21 citations

Superradiance theory and random polarisation

A. Crubellier, Sylvain Liberman, P. Pillet

Describes a theoretical study of the polarisation properties of the superradiant light emitted on a j to j' transition between degenerate levels. Two specific orthogonal polarisation vectors are associated with each set of initial conditions and the corresponding field components are shown to evolve independently during the whole linear-emission period. Due to a quenching effect, the polarisation of the emitted light is predicted to be identical to one of the two specific polarisations of the superradiant system if the intensities of the two field components are not equal during this period. If, on the other hand, the two intensities remain equal, a spontaneous symmetry breaking is expected to occur and consequently the polarisation of the superradiant light is expected to vary randomly from pulse to pulse.

Journal of Physics B Atomic and Molecular Physics•Sep 28, 1986•19 citations

Superradiance and subradiance. IV. Atomic cascades between degenerate levels

A. Crubellier, D Pavolini

For pt.III see ibid., vol.20, p.971 (1987). This paper is the fourth in a series devoted to the theoretical study of subradiance, i.e. of the cooperative inhibition of spontaneous emission. It first describes how the main results of the first paper have been developed in the general case of j to j' transitions between degenerate levels. In particular, the link between statistical mixing and symmetry properties is now derived in the general case of n-level atoms. The authors also explain how these results have allowed them to conceive the experiment which has recently provided the first evidence for the subradiance phenomenon, in the case of the 3 / 2 to 1 / 2 to 1 / 2 cascade of atomic gallium. The specific influence of the degenerate transitions which are associated with the Zeeman transitions of same polarisation is then discussed in a simplified example. Numerical simulations corresponding to the case of the experiment and to similar cases are finally presented and analysed.

Journal of Physics B Atomic and Molecular Physics•Apr 14, 1987•21 citations

Superradiance and subradiance. II. Atomic systems with degenerate transitions

A. Crubellier, D Pavolini

For pt.I see ibid., vol.18, p.3811 (1985). This paper is the second of a theoretical study of subradiance, i.e. of the cooperative inhibition of spontaneous emission by a destructive interatomic interference, a phenomenon which has recently been observed. It is devoted to the particular case of atomic systems with degenerate transitions, i.e. with several transitions of the same frequency and the same polarisation. The interatomic interference which then occurs between the different transitions is responsible, when destructive, for a new sort of subradiance. The phenomenon is studied for a few typical level configurations, using both quantum mechanical and semiclassical models. The first example concerns a four-level configuration with two transitions of the same frequency and polarisation. The other examples concern three-level configurations with a degenerate transition; in the case of the 'degenerate' cascade, new superradiant beats and subradiance effects are predicted.

Journal of Physics B Atomic and Molecular Physics•Jul 28, 1986•29 citations

Observation of superradiance in Rb vapour

J Marek

Using laser excitation of the 6 2 P levels in the natural isotopic mixture of Rb atoms, modulation of superradiance intensity from some transitions to the lower levels was observed. On the transition 6 2 P 1/2 -6 2 S 1/2 this effect is interpreted as a quantum beat between the hyperfine-structure transitions of the Rb 85 and Rb 87 isotopes. A nearly 'single-pulse' superradiant signal was obtained on the 6 2 P-4 2 D transitions. When a magnetic field was applied transverse to the direction of the laser beam, the pulses obtained showed the properties forecast by two-level superradiance theory. Preliminary results are reported.

Journal of Physics B Atomic and Molecular Physics•Apr 14, 1979•40 citations

Experimental verification of the relation between the delay time and the tipping angle for a superradiant pulse

Jin-Hong Chen, Xi‐an Mao

According to Dicke's theory of superradiance, the relation between the delay time and the tipping angle for superradiant pulses can be expressed by , where is the radiation damping time constant. This relation is verified by nuclear magnetic resonance (NMR) experiments on a normal water sample. The radiation damping time and the delay time are independently measured, and the tipping angle is evaluated. The tipping angle can be as big as several degrees if the spin inversion is not perfect. It can also be as small as rad, when the residual coherence in the transverse plane is destroyed by a strong field gradient pulse.

Journal of Physics D Applied Physics•Jan 1, 1999•10 citations
The authors report on an experimental study of intensity and delay fluctuations for a two-level system by analysing stochastic distribution of the polarisation of superradiant pulses emitted on the transition 6p 2 P 1 /2 to 6s 2 S 1/2 of rubidium atoms. They develop a theoretical interpretation of their results. Finally, use of these properties of polarisation fluctuations has permitted one to study the very beginning of the superradiant emission and to give a new estimate of the so-called 'tipping angle'.
Describes a theoretical study of the polarisation properties of the superradiant light emitted on a j to j' transition between degenerate levels. Two specific orthogonal polarisation vectors are associated with each set of initial conditions and the corresponding field components are shown to evolve independently during the whole linear-emission period. Due to a quenching effect, the polarisation of the emitted light is predicted to be identical to one of the two specific polarisations of the superradiant system if the intensities of the two field components are not equal during this period. If, on the other hand, the two intensities remain equal, a spontaneous symmetry breaking is expected to occur and consequently the polarisation of the superradiant light is expected to vary randomly from pulse to pulse.
For pt.III see ibid., vol.20, p.971 (1987). This paper is the fourth in a series devoted to the theoretical study of subradiance, i.e. of the cooperative inhibition of spontaneous emission. It first describes how the main results of the first paper have been developed in the general case of j to j' transitions between degenerate levels. In particular, the link between statistical mixing and symmetry properties is now derived in the general case of n-level atoms. The authors also explain how these results have allowed them to conceive the experiment which has recently provided the first evidence for the subradiance phenomenon, in the case of the 3 / 2 to 1 / 2 to 1 / 2 cascade of atomic gallium. The specific influence of the degenerate transitions which are associated with the Zeeman transitions of same polarisation is then discussed in a simplified example. Numerical simulations corresponding to the case of the experiment and to similar cases are finally presented and analysed.
For pt.I see ibid., vol.18, p.3811 (1985). This paper is the second of a theoretical study of subradiance, i.e. of the cooperative inhibition of spontaneous emission by a destructive interatomic interference, a phenomenon which has recently been observed. It is devoted to the particular case of atomic systems with degenerate transitions, i.e. with several transitions of the same frequency and the same polarisation. The interatomic interference which then occurs between the different transitions is responsible, when destructive, for a new sort of subradiance. The phenomenon is studied for a few typical level configurations, using both quantum mechanical and semiclassical models. The first example concerns a four-level configuration with two transitions of the same frequency and polarisation. The other examples concern three-level configurations with a degenerate transition; in the case of the 'degenerate' cascade, new superradiant beats and subradiance effects are predicted.
Using laser excitation of the 6 2 P levels in the natural isotopic mixture of Rb atoms, modulation of superradiance intensity from some transitions to the lower levels was observed. On the transition 6 2 P 1/2 -6 2 S 1/2 this effect is interpreted as a quantum beat between the hyperfine-structure transitions of the Rb 85 and Rb 87 isotopes. A nearly 'single-pulse' superradiant signal was obtained on the 6 2 P-4 2 D transitions. When a magnetic field was applied transverse to the direction of the laser beam, the pulses obtained showed the properties forecast by two-level superradiance theory. Preliminary results are reported.
According to Dicke's theory of superradiance, the relation between the delay time and the tipping angle for superradiant pulses can be expressed by , where is the radiation damping time constant. This relation is verified by nuclear magnetic resonance (NMR) experiments on a normal water sample. The radiation damping time and the delay time are independently measured, and the tipping angle is evaluated. The tipping angle can be as big as several degrees if the spin inversion is not perfect. It can also be as small as rad, when the residual coherence in the transverse plane is destroyed by a strong field gradient pulse.