Intervenant: Daniele Fontanari (LMPA Joseph Liouville) ------------ date: jeudi 26 mai, 14h, Calais ---- Titre: Quantum mechanics in the phase space: towards a quantum ----- Dzhanibekov effect Abstract: --------- In a first approximation, found to be in good agreement with experimental data, molecules can be described as rigid bodies which, from a classical point of view, are characterized by a rich geometrical structure and exhibit interesting phenomena (integrability, strong anisochronicity, presence of unstable equilibria and separatrices...). The aim of this talk is to introduce the classical and the quantum descriptions of the system, in order to uncover the correlation between the two frameworks through their dynamical similarities. As a concrete example the Dzhanibekov effect, which classically is described by a periodic flip of the unstable axis between two unstable equilibrium positions under particular initial conditions of the system, is considered. The problem of giving a phase space description of the system consistent with its quantum nature is addressed and the use of coherent states is proposed as a solution. After the link between classical and quantum dynamics has been established, the theoretical (existence of different kinds of coherent states) and experimental (creation of a coherent state in the laboratory, detection of the quantum state after the evolution) challenges that should be faced in the future will be briefly introduced.