Nonclassical Photon Statistics in Single-Molecule Fluorescence at Room Temperature. L. Fleury, J. Segura, G. Zumofen, B. Hecht and U. P. Wild in Phys. Rev. Lett. 84:1148 (2000).

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Reports the antibunching of a single molecule (concretely, a single terrylene molecule in a p-terphenyl crystal) at room temperature. In the words of the Authors:

quantum effects can be investigated using a desktop-scale apparatus at ambient conditions

This became technically possible by thwarting the rapid photo-bleaching of their particular combo.

They see a neat and clean small-time antibunching, as well as bunching elbows due to what they call "intersystem crossing" (a third level).

They rely on Reynaud's method[1] to compute long-time delay correlations, and give quite some detail about the actual procedure (e.g., see their Fig. 3 plotting binning events).

Despite a more complex sketch for the model assumed—featuring loops and sophisticated level structures—

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they actually use the standard bi-exponential $g^{(2)}(\tau)$ model from three states[2]

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There is also a Section on sub/super-Poissonian statistics (Fig. 4).


  1. La fluorescence de résonance: étude par la méthode de l'atome habillé. S. Reynaud in Annales de Physique 8:351 (1983).
  2. Correlations in light emitted by three-level atoms. D. T. Pegg, R. Loudon and P. L. Knight in Phys. Rev. A 33:4085 (1986).