Dynamique ultra rapide des électrons dans les materiaux fortemenet corrélés

par Niloufar Nilforoushan

Projet de thèse en Physique

Sous la direction de Marino Marsi et de Evangelos Papalazarou.

Thèses en préparation à Paris Saclay , dans le cadre de École doctorale Physique en Île-de-France (Paris) , en partenariat avec Laboratoire de Physique des Solides (laboratoire) et de Université Paris-Sud (établissement de préparation de la thèse) depuis le 01-10-2015 .

  • Titre traduit

    Ultrafast Electron Dynamics in Strongly Correlated Materials

  • Résumé

    Understanding phase transitions among metallic, isulating and super conducting states in materials characterized by the presence of strong electron correlation is one of the basic questions of condensed matter physics. One of the challenges in the experimental study of the systems is the separation of the different degrees of freedom (electron, lattic, spin) determining their phase diagram as well as their phase transition. The development of the femtosecond laser psources makes it possible to tackle this problem by using time as the discriminating parameter among these different degrees of freedom. Pump-probe spectroscopies based on the fs light sources are applied to observe the dynamical evolution of the electronic propoerties on the time scale of lattice vibration. This offers the possibility of decoupling lattice and electronic degrees of freedom in a transient and reversible way, thus giving acces to basic parameters of the physics of strongly correlated systems like for instance electron-phonon coupling. For some of these materials like for instance Mott-Hubbard compounds, one can also observe the temporal evolution of phase transitions, and disclose the novel aspects of their nature. In this Ph.D project, protype strongly correlated materials, such as (V1-xCrx)2O3 and BaCo1-xNixS2 will be studied with the novel ultrafast spectroscopy setups developed in the Paris- Saclay campus.