Process of velocity locking of nonlinear incoherent waves in an optical fiber

International audience

KAM techniques and resonances

International audience

On the topology of adiabatic passage

We examine the topology of eigenenergy surfaces characterizing the population transfer processes based on adiabatic passage. We show that this topology is the essential feature for the analysis of the population transfers and the prediction of its final result. We reinterpret diverse known processes, such as stimulated Raman adiabatic passage (STIRAP), frequency-chirped adiabatic passage and Stark-chirped rapid adiabatic passage (SCRAP). Moreover, using this picture, we display new related possibilities of transfer. In particular, we show that we can selectively control the level which will be populated in STIRAP process in Lambda or V systems by the choice of the peak amplitudes or the pul…

The U(p+1) Formalism Applied to The Vibrational Hamiltonians of Nonlinear AB2 Molecules

Singular tori as attractors of four-wave interaction systems

International audience

Influence of Unequal Oscillator Strenghts on Stimulated Raman Adiabatic Passage through Bright State

The problem of the coherent control of atomic states, preparation of atoms in a stable superposition state, and atomic population transfer has attracted much attention in the last decade. One of the main motivations is associated with the rapid development of the field of quantum computing. One of the key problems of quantum information processing is the construction of given coherent superposition atomic states in a macroscopic volume. Stimulated Raman adiabatic passage (STIRAP) [1] is considered to be the most common method for atomic population transfer in quantum systems. Being analyzed in detail on various quantum systems from both theoretical and experimental points of view, this meth…

From atomic to molecular Bose-Einstein condensates: a physically realizable term-crossing model for cold atom association

Using an exact third-order NL di®erential equation for the molecular state probability, we develop a variational approach which enables us to construct highly accurate analytic approximations describing time dynamics of the coupled atom-molecular system in each of the interaction regimes. We show that the approximation describing time evolution of the molecular state probability both in the weak interaction limit and in the large detuning regime of the strong interaction limit can be written as a sum of two distinct terms; the ¯rst one, being a solution to a limit ¯rst-order NL equation, e®ectively describes the process of the molecule formation while the second one, being a scaled solution…

Rotational excitation with femtosecond pulses : from high resolution spectroscopy to molecular alignment

International audience

Fermi-type interaction in molecular and atomic Hamiltonians. Application to molecular systems and Bose-Einstein condensates.

International audience; We present a simple prescription to build phenomenological Hamiltonians describing Fermi-type interactions and apply the developed formalism to two distinct physical systems. First, in a very simple way, we derive equations describing time dynamics of two coherently coupled Bose-Einstein condensates. Further, for bent XY2 molecules, we reproduce all the experimental data with an excellent precision.

The U(p+1) Formalism Applied to The Vibrational Hamiltonians of Nonlinear ABC Molecules

Uniform analytic description of dephasing effects in two-state transitions

International audience

Verrouillage de vitesses d'ondes non-linéaires incohérentes dans une fibre optique

National audience

Efficient orientation of molecules

Controle de processus quantiques par impulsions laser intenses : transfert sélectif de population, alignement moléculaire et information quantique