The nonlinear optical properties of a magneto-exciton in a strained Ga_(0.2)In_(0.8)As/GaAs quantum dot  

作　　者：N.R.Senthil Kumar A.John Peter Chang Kyoo Yoo 

机构地区：[1]Department of Physics,SBM College of Engineering and Technology [2]Department of Physics,Govt.Arts College,Melur-625 106,Madurai,India [3]Center for Environmental Studies/Green Energy Center,Deptartment of Environmental Science and Engineering,College of Engineering,Kyung Hee University,Seocheon-dong 1,Giheung-gu,Yongin-Si,Gyeonggi-Do,446-701,South Korea

出　　处：《Chinese Physics B》2013年第10期479-485,共7页中国物理B（英文版）

摘　　要：The magnetic field-dependent heavy hole excitonic states in a strained Gao.2Ino.sAs/GaAs quantum dot are investi- gated by taking into account the anisotropy, non-parabolicity of the conduction band, and the geometrical confinement. The strained quantum dot is considered as a parabolic dot of InAs embedded in a GaAs barrier material. The dependence of the effective excitonic g-factor as a function of dot radius and the magnetic field strength is numerically measured. The interband optical transition energy as a function of geometrical confinement is computed in the presence of a mag- netic field. The magnetic field-dependent oscillator strength of interband transition under the geometrical confinement is studied. The exchange enhancements as a function of dot radius are observed for various magnetic field strengths in a strained Gao.2Ino.sAs/GaAs quantum dot. Heavy hole excitonic absorption spectra, the changes in refractive index, and the third-order susceptibility of third-order harmonic generation are investigated in the Gao.2Ino.8As/GaAs quantum dot. The result shows that the effect of magnetic field strength is more strongly dependent on the nonlinear optical property in a low-dimensional semiconductor system.The magnetic field-dependent heavy hole excitonic states in a strained Gao.2Ino.sAs/GaAs quantum dot are investi- gated by taking into account the anisotropy, non-parabolicity of the conduction band, and the geometrical confinement. The strained quantum dot is considered as a parabolic dot of InAs embedded in a GaAs barrier material. The dependence of the effective excitonic g-factor as a function of dot radius and the magnetic field strength is numerically measured. The interband optical transition energy as a function of geometrical confinement is computed in the presence of a mag- netic field. The magnetic field-dependent oscillator strength of interband transition under the geometrical confinement is studied. The exchange enhancements as a function of dot radius are observed for various magnetic field strengths in a strained Gao.2Ino.sAs/GaAs quantum dot. Heavy hole excitonic absorption spectra, the changes in refractive index, and the third-order susceptibility of third-order harmonic generation are investigated in the Gao.2Ino.8As/GaAs quantum dot. The result shows that the effect of magnetic field strength is more strongly dependent on the nonlinear optical property in a low-dimensional semiconductor system.

关 键 词：oscillator strength EXCITON quantum dot 

分 类 号：O431.2[机械工程—光学工程]