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Sophie Meuret awarded the Favard 2017 prize by the Sfµ


The thesis of Sophie Meuret focused on the study of the emission statistics of the photons created by the electron irradiation of nano-objects (cathodoluminescence). Sophie Meuret has in particular discovered a photon bunching effect specific to cathodoluminescence, an effect which she has exploited for the measurement of the lifetime of nanometric objects. This work was carried out in the STEM group of the LPS, under the direction of M. Kociak and L. Tizei.

Sophie Meuret

The thesis of Sophie Meuret is entitled "The experiment of Hanbury Brown and Twiss in a scanning electron microscope : physics and applications". Quantum optics experiments at the nanometer scale is one of the major current challenges facing research. This is particularly the case for the characterization of single photon emitters (SPE), i.e. emitters which produce only one photon at a time. During her thesis work, Sophie Meuret developed and used a Hanbury Brown and Twiss (HBT) interferometer adapted for a cathodoluminescence (CL) detection system in a scanning electron microscope (STEM). Such a system enable her to measure the time correlation function g(2)(τ) of the photons emitted after interaction between an electron and an object of interest. This has made possible to demonstrate that a particular defect of the Hexagonal Boron Nitride (hBN) was an ultraviolet SPE. Then, by studying the excitation of a large number of SPEs in hBN and diamond, she discovered a new emission phenomenon, characterized by a strong bunching effect in the photons emitted (g(2)(0) ≈35). This is in contradiction with photoluminescence (PL) measurements on such systems, which show a total absence of correlation between emitted photons (g(2)(0) ≈1). She studied this surprising effect experimentally and theoretically. One of the predictions of her theoretical study was that a simple analysis of the correlation function allows to measure accurately the lifetime of the emitters. Sophie Meuret was able to use this effect to measure the lifetime of quantum wells at the nanometer level. Finally, a large part of her thesis was devoted to the development of a theory allowing to propose experiments of quantum plasmonics in an electron microscope.

Hanbury Brown and Twiss interferometer adapted for a cathodoluminescence detection system in a scanning electron microscope.

The Favard prizes are awarded by the French Society of Microscopy (SFµ) to thesis works carried out in a french university in the domains of electronic, photonic, near-field, or atomic probe microscopy. Two prizes are awarded each two years, one to life sciences and another to science of materials.

Sophie Meuret as benefited from her collaborations with J. Garcia de Abajo (ICFO, Barcelona, Spain), F. Treussart (LAC, Orsay, France), T. Auzelle, B. Daudin and B. Gayral (Institut Néel, Grenoble, France) and H. C. Chang (Academia Sinica, Taipei, Taiwan). Her thesis was financed by the DGA, the CNRS and the Equipex TEMPOS.

References

Thèse sur HAL
Société Française des Microscopies