Disclosing the ultrafast dynamics of competing phases in high - temperature superconductors by time - resolved optical spectroscopy

Understanding the interplay between the phases present in a high-temperature superconductor (superconducting, pseudogap, strange metal and Fermi-liquid-like) is the key-concept for shining light on the nature of the superconductivity mechanisms in copper-oxide based superconductors. Here, I set the bases for addressing this physics by developing an approach based on ultrafast time-resolved optical spectroscopy in the infrared and visible spectral regions. The experiments performed disclose the real-time evolution of the optical properties while the system is suddenly brought out-of-equilibrium by an ultrashort laser pulse. The data obtained show how a competing admixture of two or more phases in a high-temperature superconductor can be created and observed evolving. Finally by using new models for interpreting the experimental results the ultrafast dynamics of the competing phases start to be revealed.