Size dependent line broadening in the emission spectra of single GaAs quantum dots: Impact of surface charges on spectral diffusion

Abstract

Making use of droplet epitaxy, we systematically controlled the height of self-assembled GaAs quantum dots by more than one order of magnitude. The photoluminescence spectra of single quantum dots revealed the strong dependence of the spectral linewidth on the dot height. Tall dots with a height of ~30 nm showed broad spectral peaks with an average width as large as ~5 meV, but shallow dots with a height of ~2 nm showed resolution-limited spectral lines (<120 micro eV). The measured height dependence of the linewidths is in good agreement with Stark coefficients calculated for the experimental shape variation. We attribute the microscopic source of fluctuating electric fields to the random motion of surface charges at the vacuum-semiconductor interface. Our results offer guidelines for creating frequency-locked photon sources, which will serve as key devices for long-distance quantum key distribution.

6 pages, 6 figures; updated figs and their descriptions

References in corpus (10)

• Charge noise and spin noise in a semiconductor quantum device
• Nuclear spin physics in quantum dots: an optical investigation
• Subnanosecond spectral diffusion measurement using photon correlation
• Symmetric quantum dots as efficient sources of highly entangled photons
• Nuclear magnetization in gallium arsenide quantum dots at zero magnetic field
• Extraction of the homogeneous linewidth of a fast spectrally diffusing line
• Optically monitored nuclear spin dynamics in individual GaAs quantum dots grown by droplet epitaxy
• A frequency-stabilized source of single photons from a solid-state qubit
• Frequency stabilization of the zero-phonon line of a quantum dot via phonon-assisted active feedback
• Locating environmental charge impurities with confluent laser spectroscopy of multiple quantum dots

Cited by in corpus (12)

• Electrical and optical control of single spins integrated in scalable semiconductor devices
• Low-Noise GaAs Quantum Dots for Quantum Photonics
• High-yield fabrication of entangled photon emitters for hybrid quantum networking using high-temperature droplet epitaxy
• Electric field induced tuning of electronic correlation in weakly confining quantum dots
• Single photon emission from droplet epitaxial quantum dots in the standard telecom window around a wavelength of 1.55 $\mu$m
• Spectral broadening in self-assembled GaAs quantum dots with narrow size distribution
• GaAs droplet quantum dots with nanometer-thin capping layer for plasmonic applications
• Laser-induced spectral diffusion and excited-state mixing of silicon T centres
• Spectral broadening of optical transitions at tunneling resonances in InAs/GaAs coupled quantum dot pairs
• Highly linear polarized emission at telecom bands in InAs/InP quantum dot-nanowires by geometry tailoring
• Diamond crystal with Y-defects: spectroscopy and transmission electron microscopy
• Surface defects in carbon-doped hexagonal boron nitride for negative-contrast direct laser writing