Excitonic Mechanism of Local Phase Transformations by Optical Pumping

• Published in: Journal of superconductivity and novel magnetism Vol. 27; no. 4; pp. 1009 - 1013
• Main Authors: Brazovskii, Serguei, Kirova, Natasha
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.04.2014; Springer Verlag
• Subjects: Channels; Characterization and Evaluation of Materials; Condensed Matter Physics; Density; Doping; Excitation; Excitons; Magnetic Materials; Magnetism; Optical pumping; Original Paper; Phase transformations; Physics; Physics and Astronomy; Strongly Correlated Systems; Superconductivity; Transformations; Exciton; Optical pumping; Self-trapping; Phase transition; phase transition; self-trapping; exciton; optical pumping
• ISSN: 1557-1939; 1557-1947; 1557-1947
• DOI: 10.1007/s10948-013-2432-9

Transformations of cooperative electronic states by impacts of optical pumping and/or electrostatic doping is a new mainstream in physics of correlated systems. Here we present a semi-phenomenological modeling of spatio-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.