Dresden 2003 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 49: Poster II

HL 49.70: Poster

Donnerstag, 27. März 2003, 16:30–19:00, HSZ/P2

Radiation lifetime modification of quantum confined excitons beyond the dipole approximation — •Kwang Jun Ahn and Andreas Knorr — Institut für theoretische Physik Sek.PN7-1, Technische Universität in Berlin, Hardenbergstr.36 10623 Berlin

Usually, for a point-like atomic emitter, whose spatial extension is much smaller than the wavelength of light, the dipole-approximation is applied. Theoretical calculations in this regime, especially under the influence of additional surfaces, agree very well with experimental results. However, for mesoscopic systems, where the spatial extension of the electron wave functions cannot be neglected in comparison to the wavelength of light, the dipole approximation is questionable.

In our presentation, the lifetimes of the quantum confined exciton is calculated. Using the center-of-mass wave quantization procedure in the 2-dimensional parabolic confinement potential, the polarization of the quantum disk is derived. Eventually, with the self-consistently calculated polarization and the Green’s function tensor for the Maxwell’s wave equation, the radiative coupling of a quantum disk in a homogeneous environment, at a single interface and in a cavity-like system are derived. The numerical results are compared with those of the dipole-like emitter and an ideal quantum well.