Eur. Phys. J. B (2016) 89: 109
https://doi.org/10.1140/epjb/e2016-60795-1

Regular Article

Coupling strength, coupling-induced asymmetry and shifts in the absorption spectrum in semiconductor quantum dots

Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics, Shanghai Jiao Tong University, Shanghai 200240, P.R. China

^a e-mail: wq@sjtu.edu.cn

Received: 7 October 2015
Received in final form: 15 January 2016
Published online: 20 April 2016

Abstract

The coupling effects on the optical absorption spectrum of semiconductor quantum dots are studied by using the standard model with valence and conduction band levels coupled to dispersive quantum phonons of infinite modes. By deducing the analytical expression of the optical absorption coefficient, the relationship between the measurable quantities and the intrinsic properties of the semiconductor quantum dot is established. By this expression, the peak position, the line shape, the linewidth, and the energy shift of the absorption spectrum of semiconductor quantum dot can be calculated precisely for a wide range of parameters. The role of coupling strength as a mechanism of absorption line asymmetry is investigated, and the calculation results clearly show the coupling-induced asymmetry in the absorption line. This analytical approach is applied to GaAs quantum dot, and the results are consistent with those of experiment observations.