Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userA novel site-controlled quantum dot system with high uniformity and narrow excitonic emission
159
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We report on the optical properties of a newly developed site-controlled InGaAs Dots in GaAs barriers grown in pre-patterned pyramidal recesses by metalorganic vapour phase epitaxy. The inhomogeneous broadening of excitonic emission from an ensemble of quantum dots is found to be extremely narrow, with a standard deviation of 1.19 meV. A dramatic improvement in the spectral purity of emission lines from individual dots is also reported (18-30 ueV) when compared to the state-of-the-art for site controlled quantum dots.
rate research
Read More
In this paper we report on the optical properties of site controlled InGaAs dots with GaAs barriers grown in pyramidal recesses by metalorganic vapour phase epitaxy. The inhomogeneous broadening of excitonic emission from an ensemble of quantum dots is found to be unusually narrow, with a standard deviation of 1.19 meV, and spectral purity of emission lines from individual dots is found to be very high (18-30 ueV), in contrast with other site-controlled systems.
We report on stacked multiple quantum dots (QDs) formed inside inverted pyramidal recesses, which allow for the precise positioning of the QDs themselves. Specifically we fabricated double QDs with varying inter-dot distance and ensembles with more than two nominally highly symmetric QDs. For each, the effect of the interaction between QDs is studied by characterizing a large number of QDs through photoluminescence spectroscopy. A clear red-shift of the emission energy is observed together with a change in the orientation of its polarization, suggesting an increasing interaction between the QDs. Finally we show how stacked QDs can help influencing the charging of the excitonic complexes.
We report on coherent resonant emission of the fundamental exciton state in a single semiconductor GaAs quantum dot. Resonant regime with picoseconde laser excitation is realized by embedding the quantum dots in a waveguiding structure. As the pulse intensity is increased, Rabi oscillation is observed up to three periods. The Rabi regime is achieved owing to an enhanced light-matter coupling in the waveguide. This is due to a emph{slow light effect} ($c/v_{g}simeq 3000$), occuring when an intense resonant pulse propagates in a medium. The resonant control of the quantum dot fundamental transition opens new possibilities in quantum state manipulation and quantum optics experiments in condensed matter physics.
Optical control of exciton fluxes is realized for indirect excitons in a crossed-ramp excitonic device. The device demonstrates experimental proof of principle for all-optical excitonic transistors with a high ratio between the excitonic signal at the optical drain and the excitonic signal due to the optical gate. The device also demonstrates experimental proof of principle for all-optical excitonic routers.
We report on the observation of spin dependent optically dressed states and optical Stark effect on an individual Mn spin in a semiconductor quantum dot. The vacuum-to-exciton or the exciton-to-biexciton transitions in a Mn-doped quantum dot are optically dressed by a strong laser field and the resulting spectral signature is measured in photoluminescence. We demonstrate that the energy of any spin state of a Mn atom can be independently tuned using the optical Stark effect induced by a control laser. High resolution spectroscopy reveals a power, polarization and detuning dependent Autler-Townes splitting of each optical transition of the Mn-doped quantum dot. This experiment demonstrates a complete optical resonant control of the exciton-Mn system.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
