We study the nonequilibrium dynamics of an electronic model with competingspin-density-wave and unconventional superconductivity in the context of ironpnictides. Focusing on the collisionless regime, we find that magnetic andsuperconducting order parameters may coexist dynamically after a sudden quench,even though the equilibrium thermodynamic state supports only one orderparameter. We consider various initial conditions concomitant with the phasediagram and in a certain regime identify different oscillatory amplitude modeswith incommensurate frequencies for magnetic and superconducting responses. Atthe technical level we solve the equations of motion for the electronic Green'sfunctions and self-consistency conditions by reducing the problem to a closedset of Bloch equations in a pseudospin representation. For certain quenchscenarios the nonadiabatic dynamics of the pairing amplitude is completelyintegrable and in principle can be found exactly.
展开▼
