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

Bunching and Antibunching in the Fluorescence of Single Nanocrystals

Gaétan Messin, Jean‐Pierre Hermier, E. Giacobino, Pierre Desbiolles, Maxime Dahan

Published Jan 1, 2001• 0 citations
OpenAlex

Abstract

The fluorescence of single colloidal CdSe quantum dots is investigated at room temperature by means of the autocorrelation function over a time scale of almost 12 orders of magnitude. At short time, the autocorrelation function shows a complete antibunching indicating single photon emission and atomic-like behavior. On longer time scales (up to tens of seconds), we measure a bunching effect due to fluorescence intermittency that can not be described by fluctuations between two states with constant rates. The autocorrelation function also exhibits a non-stationary behavior related to power-law distributions of "On" and "Off" times.

Related papers

Bunching and antibunching in the fluorescence of semiconductor nanocrystals

Gaétan Messin, Jean‐Pierre Hermier, E. Giacobino +2 more

The fluorescence of single-colloidal CdSe quantum dots is investigated at room temperature by means of the autocorrelation function over a time scale of almost 12 orders of magnitude. Over a short time scale, the autocorrelation function shows complete antibunching, indicating single-photon emission and atomiclike behavior. Over longer time scales (up to tens of seconds), we measure a bunching effect that is due to fluorescence intermittency and that cannot be described by fluctuations between two states with constant rates. The autocorrelation function also exhibits nonstationary behavior related to power-law distributions of On and Off times.

Optics Letters•Dec 1, 2001•160 citations

Photon antibunching in single CdSe/ZnS quantum dot fluorescence

Brahim Lounis, Hans A. Bechtel, Daniele Gerion +2 more

We investigate the fluorescence intensity correlation function of a single CdSe quantum dot (QD) using a start–stop experiment. We observe strong photon antibunching, a signature of non-classical light emission, over a large range of intensities (0.1–100kW/cm2). The lack of coincidence at zero time delay indicates a highly efficient Auger ionization process, which suppresses multi-photon emission in these colloidal QDs. Using careful analysis of the saturation behavior of the coincidence histograms, the absorption cross-section of a single QD has also been derived.

Chemical Physics Letters•Oct 1, 2000•339 citations

Antibunching and Excitation Lifetimes in CdSe Nanocrystals

Margaret P. Cosgriff

Using a beam-splitter and two photon detectors, we measured the cross-correlation function of a series of single nanocrystals, and found that the nanocrystals exhibit antibunching (zero correlation at zero time delay) as expected, indicating that the nanocrystals were indeed emitting only one photon at a time. Modeling the nanocrystals as a three-level energy system (ground, excited, and "dark"), we measured the characteristic time delay between photons emitted by a nanocrystal, which corresponds to the inverse of the transition rate from the excited state and the ground state. We performed this measurement using 532nm and 405nm wavelength light to excite the nanocrystals. Nanocrystals excited by 532nm wavelength light had a mean time constant of 22.7 ± 5.3ns, and those excited by 405nm wavelength light had a mean time constant of 22.4 ± 6.3ns.

•Jan 1, 2009•0 citations

Photon statistics in the fluorescence of single molecules and nanocrystals: Correlation functions versus distributions of on- and off-times

Rogier Verberk, Michel Orrit

The stream of photons emitted by a single quantum system such as a molecule or a nanocrystal is often statistically characterized by the distribution of delays between consecutive photons, or by the autocorrelation function of the intensity, or by the distributions of on- and off-times. We derive and discuss general relations between their Laplace transforms, addressing the influence of detection yield and background. Our analytical treatment applies to any distribution of delays and to random telegraph signals, including nonexponential distributions. We examine the special case of systems switching between two states characterized by different distributions of delays, where the switching can obey various statistics. We show that the second-order autocorrelation function keeps track of long-time fluctuations which are obviously lost in averaging the distributions of delays. We apply our formalism to random telegraphs, in particular to those with power-law distributions of on- and/or of off-times, which are encountered in the blinking of single semiconductor nanocrystals.

The Journal of Chemical Physics•Jul 17, 2003•131 citations

Nonclassical Radiation from a Single Quantum Dot

Peter Michler, Ataç İmamoğlu, Alper Kıraz +7 more

We report the experimental observation of photon antibunching in the photoluminescence of a chemically synthesized CdSe/ZnS quantum dot (QD) at room temperature and from a single self-assembled InAs/GaAs QD at 4 K. These results prove that a single quantum dot acts like an artificial atom, with a discrete anharmonic spectrum. Using the quantum regression theorem, we find that the normalized second-order correlation function g(2)(τ) can be described by a single exponential function in the weak-laser excitation regime. From this model we derive that the time constant of the photon antibunching signal is determined by the effective incoherent pump and recombination rates of the nonresonant optically pumped QD.

physica status solidi (b)•Jan 1, 2002•22 citations

Nonclassical Photon Statistics in Single-Molecule Fluorescence at Room Temperature

L. Fleury, Jean‐Manuel Segura, G. Zumofen +2 more

The fluorescence of single terrylene molecules in a crystalline host is investigated at room temperature by scanning confocal optical microscopy. Photon arrival times are analyzed in terms of interphoton time distributions, second order correlation functions, and the variance of the photon number probability distribution. Antibunching at short times and bunching behavior for longer times is observed, associated with sub- and super-Poissonian statistics, respectively. A rate-equation analysis of the molecular level populations indicates an accelerated reverse intersystem crossing.

Physical Review Letters•Feb 7, 2000•254 citations
The fluorescence of single colloidal CdSe quantum dots is investigated at room temperature by means of the autocorrelation function over a time scale of almost 12 orders of magnitude. At short time, the autocorrelation function shows a complete antibunching indicating single photon emission and atomic-like behavior. On longer time scales (up to tens of seconds), we measure a bunching effect due to fluorescence intermittency that can not be described by fluctuations between two states with constant rates. The autocorrelation function also exhibits a non-stationary behavior related to power-law distributions of "On" and "Off" times.
The fluorescence of single-colloidal CdSe quantum dots is investigated at room temperature by means of the autocorrelation function over a time scale of almost 12 orders of magnitude. Over a short time scale, the autocorrelation function shows complete antibunching, indicating single-photon emission and atomiclike behavior. Over longer time scales (up to tens of seconds), we measure a bunching effect that is due to fluorescence intermittency and that cannot be described by fluctuations between two states with constant rates. The autocorrelation function also exhibits nonstationary behavior related to power-law distributions of On and Off times.
We investigate the fluorescence intensity correlation function of a single CdSe quantum dot (QD) using a start–stop experiment. We observe strong photon antibunching, a signature of non-classical light emission, over a large range of intensities (0.1–100kW/cm2). The lack of coincidence at zero time delay indicates a highly efficient Auger ionization process, which suppresses multi-photon emission in these colloidal QDs. Using careful analysis of the saturation behavior of the coincidence histograms, the absorption cross-section of a single QD has also been derived.
Using a beam-splitter and two photon detectors, we measured the cross-correlation function of a series of single nanocrystals, and found that the nanocrystals exhibit antibunching (zero correlation at zero time delay) as expected, indicating that the nanocrystals were indeed emitting only one photon at a time. Modeling the nanocrystals as a three-level energy system (ground, excited, and "dark"), we measured the characteristic time delay between photons emitted by a nanocrystal, which corresponds to the inverse of the transition rate from the excited state and the ground state. We performed this measurement using 532nm and 405nm wavelength light to excite the nanocrystals. Nanocrystals excited by 532nm wavelength light had a mean time constant of 22.7 ± 5.3ns, and those excited by 405nm wavelength light had a mean time constant of 22.4 ± 6.3ns.
The stream of photons emitted by a single quantum system such as a molecule or a nanocrystal is often statistically characterized by the distribution of delays between consecutive photons, or by the autocorrelation function of the intensity, or by the distributions of on- and off-times. We derive and discuss general relations between their Laplace transforms, addressing the influence of detection yield and background. Our analytical treatment applies to any distribution of delays and to random telegraph signals, including nonexponential distributions. We examine the special case of systems switching between two states characterized by different distributions of delays, where the switching can obey various statistics. We show that the second-order autocorrelation function keeps track of long-time fluctuations which are obviously lost in averaging the distributions of delays. We apply our formalism to random telegraphs, in particular to those with power-law distributions of on- and/or of off-times, which are encountered in the blinking of single semiconductor nanocrystals.
We report the experimental observation of photon antibunching in the photoluminescence of a chemically synthesized CdSe/ZnS quantum dot (QD) at room temperature and from a single self-assembled InAs/GaAs QD at 4 K. These results prove that a single quantum dot acts like an artificial atom, with a discrete anharmonic spectrum. Using the quantum regression theorem, we find that the normalized second-order correlation function g(2)(τ) can be described by a single exponential function in the weak-laser excitation regime. From this model we derive that the time constant of the photon antibunching signal is determined by the effective incoherent pump and recombination rates of the nonresonant optically pumped QD.
The fluorescence of single terrylene molecules in a crystalline host is investigated at room temperature by scanning confocal optical microscopy. Photon arrival times are analyzed in terms of interphoton time distributions, second order correlation functions, and the variance of the photon number probability distribution. Antibunching at short times and bunching behavior for longer times is observed, associated with sub- and super-Poissonian statistics, respectively. A rate-equation analysis of the molecular level populations indicates an accelerated reverse intersystem crossing.