White Rose University Consortium logo
University of Leeds logo University of Sheffield logo York University logo

Nano-Photonic Systems Incorporating Single III-V Semiconductor Quantum Dots

DUAN, QINGQING (2019) Nano-Photonic Systems Incorporating Single III-V Semiconductor Quantum Dots. PhD thesis, University of Sheffield.

[img]
Preview
Text
Qingqing Duan-Thesis.pdf
Available under License Creative Commons Attribution-Noncommercial-No Derivative Works 2.0 UK: England & Wales.

Download (7Mb) | Preview

Abstract

This thesis focuses on III-V semiconductors single quantum dot properties and on-chip optical cavities, which are potential building blocks for integrated quantum optical circuits. A fundamental investigation of electron and nuclear spin properties in GaAs/AlGaAs nanohole-filled droplet epitaxial dots is performed using photoluminescence and photoluminescence excitation spectroscopy. A close-to-zero electron g-factor for such QDs is revealed, opening up a potential route for independent control of on-chip QD spin qubits by electrodes. Optical manipulation of the nuclear spin is achieved with an efficient dynamic nuclear polarization degree as large as 65%. The internal structural properties of this type of quantum dots is investigated using nuclear magnetic resonance spectroscopy, revealing the direction and magnitude of strain. Nuclear spin relaxation times of such dots are measured with values over 500 s, indicating a stable nuclear spin bath. Numerical simulations, theoretical model calculations and experimental investigations are applied to on-chip photonic crystal molecules, demonstrating a continuous and simple route to tune the coupling strength and mode symmetry of the coupled states using end-hole displacement. This demonstration opens up the possibility of new studies of fundamental phenomena such as spontaneous symmetry breaking, long distance radiative coupling and superradiant effects. Narrow notch filtering and the Purcell enhancement of a single QD emission are achieved in waveguide-coupled ring resonator devices. Mode structures and transmission spectra are measured using photoluminescence spectroscopy measurements. Whispering gallery mode ring resonators provide a possible route to on-chip filtering and optical switching.

Item Type: Thesis (PhD)
Keywords: semiconductors, single quantum dot, electron and nuclear spin properties, nano-photonic, optical cavities.
Academic Units: The University of Sheffield > Faculty of Science (Sheffield) > Physics and Astronomy (Sheffield)
Identification Number/EthosID: uk.bl.ethos.784726
Depositing User: MISS QINGQING DUAN
Date Deposited: 16 Sep 2019 14:15
Last Modified: 25 Sep 2019 20:09
URI: http://etheses.whiterose.ac.uk/id/eprint/24789

You do not need to contact us to get a copy of this thesis. Please use the 'Download' link(s) above to get a copy.
You can contact us about this thesis. If you need to make a general enquiry, please see the Contact us page.

Actions (repository staff only: login required)