The Sfμ 2017 Favard prize, Physics, rewards the thesis work of Sophie Meuret
The thesis of Sophie Meuret is entitled "The experiment of Hanbury Brown and Twiss in a scanning electron microscope: physics and applications". Being able to perform quantum optics experiments at the nanometer scale is one of the major current challenges of research. This is particularly the case for the characterization of single photon emitters (SPE), that is to say emitters which emit 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 makes it possible 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) (τ) ≈35). This is in flagrant contradiction with photoluminescence (PL) measurements on such systems, which show a total absence of correlation between emitted photons (g(2) (τ) ≈1). She studied this surprising effect experimentally and theoretically. One of the predictions of his theoretical study was that a simple analysis of the correlation function makes it possible to accurately measure the lifetime of the emitters. Sophie Meuret was able to use this effect to measure the lifetime at the nanometer level of quantum wells. 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.