Dynamical patterns of phase transformations from self-trapping of quantum excitons

Yi, Tianyou1; Kirova, Natasha2,4; Brazovskii, Serguei3,4

2015-03

10.1016/j.physb.2014.11.043

PHYSICA B-CONDENSED MATTER   影响因子和分区

0921-4526

1873-2135

Phase transitions induced by short optical pulses is a new mainstream in studies of cooperative electronic states. Its special realization in systems with neutral-ionic transformations stands out in a way that the optical pumping goes to excitons rather than to electronic bands. We present a semi-phenomenological modeling of spacio-temporal effects applicable to any system where the optical excitons are coupled to a symmetry breaking order parameter. In our scenario, after a short initial pulse of photons, a quasi-condensate of excitons appears as a macroscopic quantum state which then evolves interacting with other degrees of freedom prone to instability. This coupling leads to self-trapping of excitons; 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 system is stratified in domains which evolve through dynamical phase transitions and may persist even after the initiating excitons have recombined. We recover dynamic interplays of fields such as the excitons wave function, electronic charge transfer and polarization, lattice dimerization. (C) 2014 Elsevier B.V. All rights reserved.

Pump induced phase transition Dynamical phase transition Neutral-ionic Exciton Self trapping

SCI ; CPCI-S ; EI

英语

第一

Physics

Physics, Condensed Matter

WOS:000350808300016

ELSEVIER SCIENCE BV

20151000604228

Charge transfer ; Degrees of freedom (mechanics) ; Optical pumping ; Phase transitions ; Wave functions

Physical Chemistry:801.4 ; Chemical Reactions:802.2 ; Mathematics:921 ; Mechanics:931.1

PHYSICS

Web of Science

1.South Univ Sci & Technol China, Shenzhen 518055, Guangdong, Peoples R China
2.Univ Paris 11, CNRS, LPS, UMR 8626, F-91405 Orsay, France
3.Univ Paris 11, CNRS, LPTMS, UMR 8502, F-91405 Orsay, France
4.Univ Fed Rio Grande do Norte, Int Inst Phys, BR-59078400 Natal, RN, Brazil

Yi, Tianyou,Kirova, Natasha,Brazovskii, Serguei. Dynamical patterns of phase transformations from self-trapping of quantum excitons[J]. PHYSICA B-CONDENSED MATTER,2015,460:73-78.

Yi, Tianyou,Kirova, Natasha,&Brazovskii, Serguei.(2015).Dynamical patterns of phase transformations from self-trapping of quantum excitons.PHYSICA B-CONDENSED MATTER,460,73-78.

Yi, Tianyou,et al."Dynamical patterns of phase transformations from self-trapping of quantum excitons".PHYSICA B-CONDENSED MATTER 460(2015):73-78.