Theory Of Indirect Excitons Photoluminescence In Elevated Quantum Trap

In recent years, the exciton Bose-Einstein condensation experiments have made great progress, especially observed a variety of new phenomena. It causes great concern and becomes a hot issue in condensed matter theory. This paper investigates one of the unusual experiment phenomenon, while the experimental data has published in Nano. Letter, 2009, 9: 2094.The experiment has measured the photoluminescence spectra of indirect excitons in elevated quantum traps, and observed abnormal changes in position of the two emission peak intensity and peak with the excitation intensity, reflecting the intrinsic properties of excitons. The analysis reveals it is caused by exciton energy relaxation resulting in phonon bottleneck effect and exciton nonlinear interactions. Thus the paper sets up a rate equation and a nonlinear Schrodinger equation to describe the behavior of excitons, and compared with the experiment results. The paper is organized as following:Firstly, it introduces the development process of the Bose-Einstein condensation(BEC), the exciton Bose-Einstein condensation research status and indirect excitons in elevated traps phenomenon photoluminescence experiments, and gives the contents of this subject.Secondly, review various theories and models of the exciton BEC, and introduces the basic theory required in the article.Again, the establishment of a second-order rate equation obtains the relationship of the intensity of excitation spectra peaks with the excitation power by numerical analysis. By solving nonlinear Schrodinger equation, obtains the position of peak dependence of the excitation power.Finally, researches of the paper are summarized.