Excitonic Mechanism of Local Phase Transformations by Optical Pumping

Serguei Brazovskii 1 Natasha Kirova 2

Journal of Superconductivity and Novel Magnetism, Springer Verlag (Germany), 2014, 27, pp.1009 - 1013. <10.1007/s10948-013-2432-9>

Transformations of cooperative electronic states by impacts of optical pumping or/and electrostatic doping is a new mainstream in physics of correlated systems. Here we present a semi-phenomenological modelling of spacio-temporal effects in a system where the light absorption goes through a channel creating the excitons – intra-molecular ones or bound electron-hole pairs -and finally the condensate of optical excitons feeds and stimulates phase transformations. Interacting with a near-critical order parameter and deformations, the excitons are subject to self-trapping. That locally enhances their density which can surpass a critical value to trigger the phase transformation, even if the mean density is below the required threshold. The model can be used e.g. as a simplified version of optically induced neutral-ionic transitions in organic chain compounds.

  • 1. LPTMS - Laboratoire de Physique Théorique et Modèles Statistiques
  • 2. LPS - Laboratoire de Physique des Solides