NON-EQUILIBRIUM STUDY OF CORRELATED HONEYCOMB IRIDATES WITH STRONG SPIN-ORBIT COUPLING.

Transition-metal oxides (TMO) are one of the most studied class of materials, as a consequence of their rich and exotic physical properties, mainly determined by the strong electronic correlations of the metal d electrons. In this thesis I discuss about a particular 5d compound, sodium iridates, where spin-orbit coupling Coulomb repulsion and bandwidth are in comparable energy scales. Furthermore, these systems are Mott insulators and present a zigzag antiferromagnetic transition below TN 15 K. Here we tackle the physics of sodium iridates by adopting a nonequilibrium viewpoint based on the use of ultrafast light pulses combined in the so-called pump-probe experimental configuration. The aim is to perturb the antiferromagnetic state of the system via the excitation with a pump pulse and to observe the ultrafast recovery of the ground state by means of a second delayed probe pulse. Specifically, we will measure the dynamics of the pump-induced reflectivity variation in the zigzag antiferromagnetic and normal states as a function of the probe energy and as a function of time delay between the pump and the probe pulses.