A semi-phenomenological model of how a dense ensemble of optically pumped excitons in an insulator evolves into a charge-transfer ordered state. A Ginzburg-Landau order parameter is coupled to a macroscopic exciton-condensate wavefunction and to lattice displacements, so that exciton self-trapping drives the local density past a critical value and triggers a phase transformation that stratifies the crystal into domains persisting after the excitons recombine. The model also identifies a dynamical phase-locking transition that demarcates the Bose-Einstein-condensate and excitonic-insulator regimes.
A semi-phenomenological model of how a dense ensemble of optically pumped excitons in an insulator evolves into a charge-transfer ordered state. A Ginzburg-Landau order parameter is coupled to a macr…