Theory for wavelength-resolved photon emission statistics in single-molecule spectroscopy

TL;DR

This paper develops a theoretical framework for analyzing wavelength-resolved photon emission statistics in single-molecule spectroscopy, revealing how detector bandwidth influences photon correlations and anti-bunching phenomena.

Contribution

It introduces a method to calculate photon emission statistics considering photon frequencies, highlighting the impact of detector bandwidth on observed quantum effects.

Findings

Photon statistics depend strongly on detector bandwidth.

Anti-bunching arises from correlations between photons of different frequencies.

The theory explains non-intuitive photon emission behaviors in single-molecule experiments.

Abstract

We derive the moment generating function for photon emissions from a single molecule driven by laser excitation. The frequencies of the fluoresced photons are explicitly considered. Calculations are performed for the case of a two level dye molecule, showing that measured photon statistics will display a strong and non-intuitive dependence on detector bandwidth. Moreover, it is demonstrated that the anti-bunching phenomenon, associated with negative values of Mandel's Q-parameter, results from correlations between photons with well separated frequencies.