Fine structure splitting analysis of cavity-enhanced telecom-wavelength InAs quantum dots grown on a GaAs(111)A vicinal substrate

Abstract

The effcient generation of entangled photons at telecom wavelength is crucial for the success of many quantum communication protocols and the development of fiber-based quantum networks. Entangled light can be generated by solid state quantum emitters with naturally low fine structure splitting, such as highly symmetric InAs quantum dots (QDs) grown on (111)-oriented surfaces. Incorporating this kind of QDs into optical cavities is critical to achieve sufficient signal intensitiesfor applications, but has so far shown major complications. In this work we present droplet epitaxy of telecom-wavelength InAs QDs within an optical cavity on a vicinal (2° miscut) GaAs(111)A substrate. We show a remarkable enhancement of the photon extraction efficiency compared to previous reports together with a reduction of the density that facilitates the isolation of single spectral lines. Moreover, we characterise the exciton fine structure splitting and employ numerical simulations under the framework of the empirical pseudopotential and configuration interaction methods to study the impact of the miscut on the optical properties of the QDs. We demonstrate that the presence of miscut steps influences the polarisation of the excitonic states and introduces a preferential orientation in the $C_{3v}$ symmetry of the surface.

References in corpus (9)

• The Quantum Internet
• Droplet Epitaxy of Semiconductor Nanostructures for Quantum Photonic Devices
• Inversion of exciton level splitting in quantum dots
• Excitons, biexcitons and trions in self-assembled (In,Ga)As/GaAs quantum dots: Recombination energies, polarization and radiative lifetimes versus dot height
• High performance single-photon sources at telecom wavelength based on broadband hybrid circular Bragg gratings
• Design study for an efficient semiconductor quantum light source operating in the telecom C-band based on an electrically-driven circular Bragg grating
• Numerical optimization of single-mode fiber-coupled single-photon sources based on semiconductor quantum dots
• Telecom-wavelength InAs QDs with low fine structure splitting grown by droplet epitaxy on GaAs(111)A vicinal substrates
• Enhancing the photon-extraction efficiency of site-controlled quantum dots by deterministically fabricated microlenses