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Xavier Brokmann

Publications and source records attributed to Xavier Brokmann.

3 recordsLinked to original sources

Revealing single emitter spectral dynamics from intensity correlations in an ensemble fluorescence spectrum

We show that the single emitter linewidth underlying a broadened ensemble emission spectrum can be extracted from correlations among the stochastic intensity fluctuations in the ensemble spectrum. Spectral correlations can be observed at high temporal and spectral resolutions with a cross-correlated pair of avalanche photodiodes placed at the outputs of a scanning Michelson interferometer. As illustrated with simulations in conjunction with Fluorescence Correlation Spectroscopy, our approach overcomes ensemble and temporal inhomogeneous broadening to provide single emitter linewidths, even for emitters under weak, continuous, broadband excitation.

physics.optics

Photon-correlation Fourier spectroscopy

We describe a method to probe the spectral fluctuations of a transition over broad ranges of frequencies and timescales with the high spectral resolution of Fourier spectroscopy, and a temporal resolution as high as the excited state lifetime, even in the limit of very low photocounting rates. The method derives from a simple relation between the fluorescence spectral dynamics of a single radiating dipole and its fluorescence intensity correlations at the outputs of a continuously scanning Michelson interferometer. These findings define an approach to investigate the fast fluorescence spectral dynamics of single molecules and other faint light sources beyond the time-resolution capabilities of standard spectroscopy experiments.

physics.optics

Multi-island single-electron devices from self-assembled colloidal nanocrystal chains

We report the fabrication of multi-island single-electron devices made by lithographic contacting of self-assembled alkanethiol-coated gold nanocrystals. The advantages of this method, which bridges the dimensional gap between lithographic and NC sizes, are (1) that all tunnel junctions are defined by self-assembly rather than lithography and (2) that the ratio of gate capacitance to total capacitance is high. The rich electronic behavior of a double-island device, measured at 4.2 K, is predicted in detail by combining finite element and Monte Carlo simulations with the standard theory of Coulomb blockade with very few adjustable parameters.

cond-mat.other