Recent experimental developments with ultrafast pump-probe experiments have turned the electromagnetic radiation from traditional spectroscopic probe into a powerful tool to control and manipulate strongly correlated materials.
A striking example is provided by light-induced superconductivity, observed in a number of compounds at temperaturesfar higher than in thermal equilibrium. In this talk I will discuss the nonequilibrium dynamics of a prototype model of strongly correlated electrons, the single-band Hubbard model, driven by a time-periodic modulation of its interaction, mimicking the effect of a continuous pump excitation.
I will show that starting from the Mott insulating regime and depending on the frequency of the drive the system can either heats up exponentially fast or remain trapped into a long-lived metastable state with unusual nonequilibrium properties, including a population inversion of the doublon/holon band. In this regime a weak energy dissipation due to phonons leads to a massive productions of doublon excitations, well above the maximum thermal-equilibrium value. We interpret this effect as an enhancement of local pairing correlations, a precursor of truly long-ranged staggered superconducting correlations. This suggests the possibility of realizing the elusive eta-pairing superconducting phase in optically pumped Mott Insulators.
