Chirping of superconducting order parameter using compression-based nonequilibrium Greens function

We study photodoped superconductors using dynamical mean-field theory with second Born approximation as the impurity solver. We excite the superconducting system with a laser pulse and show that the order parameter decays super-exponentially for strong pulses, and oscillates for weak pulses. We attribute the oscillation to the amplitude mode excitations of the order parameter, which slows down as the system evolves, a phenomenon known as chirping. The chirping gets more enhanced the more we approach to the dynamical critical point. Finally, we show that the chirping phenomenon can be measured using optical pump-probe experiments in photodoped superconductors. To integrate our results to the long time scales required to study this phenomenon, we have developed a generelization of the compressed representation integration method that allows for matrix valued Green's functions.