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

Wave-function collapse due to null measurements: The origin of intermittent atomic fluorescence

Massimo Porrati B, Seth Putterman

Published Jul 1, 1987• 100 citations
Publisher

Abstract

The observation of no photons emitted by a fluorescing multilevel atom dramatically affects its future evolution. This collapse of the quantum state due to measurements with a null result is the cause of intermittent atomic fluorescence even when the exciting field is arbitrarily coherent.
DOI
10.1103/physreva.36.929

Related papers

Coherent intermittency in the resonant fluorescence of a multilevel atom

Massimo Porrati B, Seth Putterman

Time correlations in the fluorescence of a multilevel atom are studied in terms of the quantum statistics which describe the emission of the next photon. The next photon equations are substantially simpler than the a photon equations (or so-called optical Bloch equations) yet they contain phase information lost in the averaging procedure that yields the a photon equations. Employing the next photon equations we present a quantum formalism in which the time development of the wave function of the atom is dramatically modified by the observation of a dark period. This ``collapse'' of the quantum state due to measurements with a null result (such as the failure to record events in a photodetector) is the cause of intermittent atomic fluorescence even when the exciting field is arbitrarily coherent. The next photon and a photon formalisms are contrasted and applied to photon antibunching. The phenomenon of photon bunching which characterizes sideband correlations is also calculated. Observable effects particular to the coherent intermittency are emphasized.

Physical Review A•Mar 1, 1989•37 citations

Intermittent atomic fluorescence

Harry J. Kimble, Richard J. Cook, Ann Laurie Wells

In a single-atom double-resonance experiment involving a strong and a weak transition, quantum jumps on the weak transition cause the resonance fluorescence of the strong transition to turn on and off randomly in time when observed over intervals long compared to the lifetime of the strong transition but short compared to that of the weak transition. Here we present a theory of this intermittent atomic fluorescence for the case of coherent excitation.

Physical Review A•Oct 1, 1986•84 citations

Interrupted fluorescence, quantum jumps and wavefunction collapse. II

David Thomas Pegg, P. L. Knight

For pt.I see Phys. Rev. A, vol.37, p.4303 (1988). The principle of wavefunction collapse by non-detection of photons leads to simple but rigorous expressions for the average dark and bright periods, T D and T B , of intermittent quantum jump fluorescence from a V-configuration three-level atom. Here further consequences of this principle are explored, including: the derivation of some new correlation functions which exhibit the physical characteristics of extended dark and bright periods; the expressions for T D and T B when one transition is driven coherently and the other incoherently; and a general expression for the characteristic time to be sure that a quantum jump has occurred for any type of driving field.

Journal of Physics D Applied Physics•Oct 14, 1988•8 citations

Regimes of Coherent Intermittency in the Next Quantum Jump of a Multilevel System

Massimo Porrati B, Nicholas E. Penthorn, John Rooney +2 more

In an externally driven multilevel quantum system observation that the NEXT jump has not yet happened affects its future development. In previous work [Phys. Rev. A36, 929 (1987)] it was shown that this class of measurement makes it possible to observe remarkably long dark intervals -- or intermittency -- in the atomic fluorescence of an atom with 3 or more levels. Those calculations were carried out when the driven oscillations or Rabi flopping between the ground state and a strongly fluorescing state were fast compared to its lifetime. In systems with solid state Qubits the accessible parameter space is generally limited to the regime where oscillations are slower than the lifetime. In this paper we evaluate intermittency in atomic transitions, due to measurements with a null result, in this limit. During the dark periods the wave function of the continuously measured multilevel system is coherent.

arXiv:1810.03225•Oct 7, 2018•1 citation

Wave Function Collapse in Atomic Physics

DT Pegg

Wave function collapse has been a contentious concept in quantum mechanics for a considerable time. Here we show examples of how the concept can be used to advantage in predicting the statistical results of three experiments in atomic physics and quantum optics: photon antibunching, single-photon phase difference states and interrupted single-atom fluorescence. We examine the question of whether or not collapse is 'really' a physical process, and discuss the consequences of simply omitting it but including the observer as a part of the overall system governed by the laws of quantum mechanics. The resulting entangled world does not appear to be inconsistent with experience.

Australian Journal of Physics•Feb 1, 1993•8 citations

Interrupted fluorescence, quantum jumps, and wave-function collapse

David Thomas Pegg, P. L. Knight

The phenomenon of antibunching provides important support for the physical principle of the collapse of the wave function following a detection of a photon. In this paper we show that interrupted fluorescence in a three-level, V-configuration atom, with one transition strongly driven and one weakly driven, can be regarded as evidence supporting the complementary principle of ``collapse by nondetection.'' Use of this principle leads to the immediate deduction of remarkably simple general expressions for the average bright and dark periods, which allows these quantities to be calculated for both coherent and incoherent excitation without the need to solve the density-matrix equations, or even to find their long-term steady-state solutions. Thus the concept of collapse by nondetection appears to be not only valid but is also useful for predicting physically observable phenomena.

Physical Review A•Jun 1, 1988•38 citations
Time correlations in the fluorescence of a multilevel atom are studied in terms of the quantum statistics which describe the emission of the next photon. The next photon equations are substantially simpler than the a photon equations (or so-called optical Bloch equations) yet they contain phase information lost in the averaging procedure that yields the a photon equations. Employing the next photon equations we present a quantum formalism in which the time development of the wave function of the atom is dramatically modified by the observation of a dark period. This ``collapse'' of the quantum state due to measurements with a null result (such as the failure to record events in a photodetector) is the cause of intermittent atomic fluorescence even when the exciting field is arbitrarily coherent. The next photon and a photon formalisms are contrasted and applied to photon antibunching. The phenomenon of photon bunching which characterizes sideband correlations is also calculated. Observable effects particular to the coherent intermittency are emphasized.
For pt.I see Phys. Rev. A, vol.37, p.4303 (1988). The principle of wavefunction collapse by non-detection of photons leads to simple but rigorous expressions for the average dark and bright periods, T D and T B , of intermittent quantum jump fluorescence from a V-configuration three-level atom. Here further consequences of this principle are explored, including: the derivation of some new correlation functions which exhibit the physical characteristics of extended dark and bright periods; the expressions for T D and T B when one transition is driven coherently and the other incoherently; and a general expression for the characteristic time to be sure that a quantum jump has occurred for any type of driving field.
In an externally driven multilevel quantum system observation that the NEXT jump has not yet happened affects its future development. In previous work [Phys. Rev. A36, 929 (1987)] it was shown that this class of measurement makes it possible to observe remarkably long dark intervals -- or intermittency -- in the atomic fluorescence of an atom with 3 or more levels. Those calculations were carried out when the driven oscillations or Rabi flopping between the ground state and a strongly fluorescing state were fast compared to its lifetime. In systems with solid state Qubits the accessible parameter space is generally limited to the regime where oscillations are slower than the lifetime. In this paper we evaluate intermittency in atomic transitions, due to measurements with a null result, in this limit. During the dark periods the wave function of the continuously measured multilevel system is coherent.
Wave function collapse has been a contentious concept in quantum mechanics for a considerable time. Here we show examples of how the concept can be used to advantage in predicting the statistical results of three experiments in atomic physics and quantum optics: photon antibunching, single-photon phase difference states and interrupted single-atom fluorescence. We examine the question of whether or not collapse is 'really' a physical process, and discuss the consequences of simply omitting it but including the observer as a part of the overall system governed by the laws of quantum mechanics. The resulting entangled world does not appear to be inconsistent with experience.
The phenomenon of antibunching provides important support for the physical principle of the collapse of the wave function following a detection of a photon. In this paper we show that interrupted fluorescence in a three-level, V-configuration atom, with one transition strongly driven and one weakly driven, can be regarded as evidence supporting the complementary principle of ``collapse by nondetection.'' Use of this principle leads to the immediate deduction of remarkably simple general expressions for the average bright and dark periods, which allows these quantities to be calculated for both coherent and incoherent excitation without the need to solve the density-matrix equations, or even to find their long-term steady-state solutions. Thus the concept of collapse by nondetection appears to be not only valid but is also useful for predicting physically observable phenomena.