Encadrant : Athanasios Laliotis, laliotis(at)univ-paris13.fr, du LPL Université Paris13

Descriptif :

The Blackbody radiation (BBR) spectrum was at the origin of quantum mechanics at the onset of the 20th century.  BBR is obtained by considering photons as a bosonic gas that occupy the modes of the electromagnetic field according to Bose-Einstein statistics. At the dielectric-vacuum interface, the electromagnetic field also supports evanescent surface modes (so called plasmon or polariton modes), described by a local density of states that rapidly decreases away from the surface of the dielectric [1]. At the onset of the 21st century, it was shown that thermal population of evanescent modes gives a strong ‘color’ to thermal emission spectrum in the near field of the surface compared to far-field BBR. It was recently demonstrated, in our group, that the unusually coherent properties of near field thermal emission can be probed by measuring the energy level shifts of cesium atoms ~100 nm away from a sapphire surface [2].

The student is expected to understand the origins of the near field thermal spectrum of dielectrics [1], describe different methods that can be used for its experimental observation [1] and discuss its effects on atomic energies and lifetimes [2].

Sujet 2 CAT A. Laliotis