Exciton and multiexciton optical properties of single InAs/GaAs site-controlled quantum dots

Abstract

We have studied the optical properties of InAs site-controlled quantum dots (SCQDs) grown on prepatterned GaAs substrates. Since InAs nucleates preferentially on the lithography motifs, the location of the resulting QDs is determined by the pattern, which is fabricated by local oxidation nanolithography. Optical characterization has been performed on such SCQDs to study the fundamental and excited states. At the ground state different exciton complex transitions of about 500 leV linewidth have been identified and the fine structure splitting of the neutral exciton has been determined (%65 leV). The observed electronic structure covers the demands of future quantum information technologies. V C 2013 AIP Publishing LLC. [http://dx

Dephasing of InAs quantum dot p -shell excitons studied using two-dimensional coherent spectroscopy

“…1(b) 40 . These states are nearly degenerate as confirmed as multiplets observed in µPL spectra 41 . We show in the following section that these quasi-degenerate states for the p-shell are responsible for faster dephasing compared to the sshell.…”

GaAs integrated quantum photonics: Towards compact and multi‐functional quantum photonic integrated circuits

“…drilling holes into it [76][77][78][79][80][81][82][83]. This can be achieved by a combination of electron beam lithography and ion etching, by atomic force nano-lithography [84], by nanoimprint lithography [85] or by local oxidation nanolithography [86]. During subsequent regrowth the adatoms preferentially nucleate at the patterned sites and form QDs.…”

Role of re-growth interface preparation process for spectral line-width reduction of single InAs site-controlled quantum dots

“…The inset shows the spectrum of the InAs SCQD with the lowest FWHM value, 64 μeV, achieved in this work. These values represent a great improvement with respect to our previous work on site-controlled InAs nanostructures [33] where the SCQDs showed an average FWHM 870 μeV. This fivefold reduction has been obtained without increasing the distance between the optically active InAs SCQDs and the re-growth interface (15 nm in both cases) and highlights the crucial importance of the highest temperature that underwent the regrowth interface.…”

“…In this work we report on the optical properties of single InAs SCQDs grown by molecular beam epitaxy (MBE) on GaAs(001)-patterned substrates, fabricated by AFM oxidation lithography. Thermal annealing of the re-growth interface up to 530 °C and vertical stacking of the nanostructures provides an improvement of the InAs SCQD optical properties with respect to our previously studied single-layer InAs SCQDs grown on the same kind of AFM oxidation lithography-patterned substrates [33]. Micro-photoluminescence (μPL) measurements of the vertically stacked active InAs SCQDs, located 15 nm from the re-growth interface, reveal an average exciton line-width of 156 μeV with a standard deviation of 50 μeV.…”