Related papers: The Optical Activity of the Dark Exciton
We use an atomistic model to consider the effect of shape symmetry breaking on the optical properties of self-assembled InAs/GaAs quantum dots. In particular, we investigate the energy level structure and optical activity of the lowest…
Quantum dots are arguably one of the best platforms for optically accessible spin based qubits. The paramount demand of extended qubit storage time can be met by using quantum-dot-confined dark exciton: a longlived electron-hole pair with…
Excitons in alloyed nanowire quantum dots have unique spectra as shown here using atomistic calculations. The bright exciton splitting is triggered solely by alloying and despite cylindrical quantum dot shape reaches over $15~\mu$eV,…
The electronic and optical properties of self-assembled InN/GaN quantum dots (QDs) are investigated by means of a tight-binding model combined with configuration interaction calculations. Tight-binding single particle wave functions are…
The emission spectra of individual self-assembled quantum dots containing a single magnetic Mn atom differ strongly from dot to dot. The differences are explained by the influence of the system geometry, specifically the in-plane asymmetry…
Photoluminescence of a single CdSe quantum dot embedded in a ZnSe nanowire has been investigated. It has been found that the dark exciton has a strong influence on the optical properties. The most visible influence is the strongly reduced…
We investigate polarization properties of neutral exciton emission in single self-assembled InAs/GaAs quantum dots. The in-plane shape and strain anisotropy strongly couple the heavy and light hole states and lead to large optical…
The spin-flip rate that couples dark and bright excitons in self-assembled quantum dots is obtained from time-resolved spontaneous emission measurements in a modified local density of optical states. Employing this technique, we can…
We study an impact of the fine structure of the heavy--hole ground state exciton confined in semiconductor quantum dots on the photoluminescence polarization dynamics solving the relevant system of the rate equations. The presence of the…
We present both experimental and theoretical results on the influence of a magnetic field on excitons in semiconductor quantum dots. We find a pronounced difference between the strong and weak confinement regimes. For weak confinement, the…
Spatially structured light fields applied to semiconductor quantum dots yield fundamentally different absorption spectra than homogeneous beams. In this paper, we theoretically discuss the resulting spectra for different light beams using a…
We apply low temperature confocal optical microscopy to spatially resolve, and spectroscopically study a single self assembled quantum dot. By comparing the emission spectra obtained at various excitation levels to a theoretical many body…
We study the effect of an electric-field on an electron-hole pair in an asymmetric system of vertically coupled self-assembled quantum dots taking into account their non-perfect alignment. We show that the non-perfect alignment does not…
The lack of structural symmetry which usually characterizes semiconductor quantum dots lifts the energetic degeneracy of the bright excitonic states and hampers severely their use as high fidelity sources of entangled photons. We…
In this work, we theoretically investigate the optical orientation and alignment of excitons in quantum dots with weak electron-hole exchange interaction and long exciton radiative lifetimes. This particular regime is realized in…
We report on a complex nontrivial behavior of the optical anisotropy of quantum dots that is induced by a magnetic field in the plane of the sample. We find that the optical axis either rotates in the opposite direction to that of the…
The effect of Gamma-X mixing on the energy levels fine structure of indirect in k-space excitons in an ensemble of (In,Al)As/AlAs quantum dots with type I band alignment was experimentally studied. Using the methods of optical spin…
A promising method to investigate dark exciton transitions in quantum dots is presented. The optical recombination of the dark exciton is allowed when the exciton state is coupled with an individual magnetic impurity (manganese ion). It is…
The self-assembled quantum dot with lens domain has rotational symmetry but it is intrinsically asymmetric when the electron moves perpendicularly to its circular base, {\it i. e.} along the rotational axis. To characterize this asymmetry,…
A transition from a cylindrical quantum dot to a highly elongated quantum dash is theoretically studied here with an atomistic approach combining empirical tight binding for single particle states and configuration interaction method for…