Over the last two decades, intense ultrashort electromagnetic fields have enabled observing and controlling a number of emergent states in quantum materials. Some of most spectacular light-induced phenomena, such as superconducting-like phases, transient charge density wave ordering, and excitonic condensation, are found to occur in materials dominated by strong electronic correlations with a large susceptibility to external stimuli. Recently, it has been theoretically argued that quasi-one-dimensional Mott insulators might host exotic and genuinely nonequilibrium ordering phenomena upon photoexcitation, such as h-pairing superconductivity. In these systems, the light-matter interaction can promote a nonthermal population of holes and double-occupancies, but also directly modify the effective many-body interactions, such as electron hopping amplitudes and electron-electron repulsion.
In this talk, I will report about our recent ultrafast optical studies on a paradigmatic quantum chain – the quasi-1D cuprate Sr2CuO3 – and discuss implications for the realization of new driven states in photoexcited Mott insulators. First, I will discuss our observation that intense midinfrared light photons enable controlling the high harmonic emission of Sr2CuO3 by reshaping the many-body states contributing to its large optical nonlinearity. Then, I will focus on how the connection between these light-induced changes and a light-induced renormalization of effective interactions. Finally, I will show how time-resolved x-ray spectroscopy allow us to fully reconstruct the driven many-body state.
