Ilias Perakis: Time-resolving superconductivity
In solid state materials, quantum states have been mostly manipulated so far by tuning static parameters such as chemical substitution, pressure, electric or magnetic fields.Recently, “sudden” quantum quench and prethermalization have emerged as a cross cutting theme for non-equilibrium manipulation and discovery of emergent quantum states of matter. In this talk, I will discuss how Terahertz (THz) laserpulses can be used to accelerate electrons in a superconducting quantum state during few cycles of electric field oscillations,in a way controlled by electromagnetic propagation effects.By modeling directly in the time domain the transient nonlinear signals observed experimentally, I will demonstrate that THz lightwave driving of supercurrents is a universal dynamical symmetry-breaking principle that allows for observation and control of collective modes in quantum systems. In addition, it can be used to drive new non-equilibrium quantum phases such as long-lived gapless superconductivity. Light-driven Cooper-pair condensate flow during cycles of oscillation manifests itself via high harmonic generation at new frequencies forbidden by the equilibrium symmetry and allows for control of collective modes by THz-pulse shaping. I will also show how the computation of two-dimensional spectra can image quantum states and extract new information from experiments that is not easily accessible with conventional nonlinear spectroscopy.