Electronic and phononic dynamics probed by ultrafast laser spectroscopy in 1T-TaS2, SiO2 and Al2O3
The aim of this thesis is to investigate certain out-of-equilibrium phenomena in solids using pump-probe spectroscopy techniques in the visible and infrared ranges.
The work concerned different systems, firstly 1T-TaS₂ which is a highly correlated material in which we studied the formation of a new photo-induced phase.
Secondly, we carried out experiments in quartz and sapphire, which are two similar large-gap dielectrics but exhibit different out-of-equilibrium properties.
Firstly, in quartz, we sought to distinguish ultrafast phenomena such as the Kerr effect, exciton trapping and the generation of coherent optical phonons.
Finally, in sapphire, measurements in the visible and infrared revealed complex relaxation dynamics and GHz oscillations that appear to be plasmonic in nature.