eprintid: 10157370
rev_number: 14
eprint_status: archive
userid: 699
dir: disk0/10/15/73/70
datestamp: 2022-12-08 12:25:21
lastmod: 2022-12-08 12:25:21
status_changed: 2022-12-08 12:25:21
type: thesis
metadata_visibility: show
sword_depositor: 699
creators_name: Duan, Jingyu
title: Gate-based sensing of silicon quantum dot devices towards 2D scaling
ispublished: unpub
divisions: C05
divisions: F46
divisions: B04
divisions: UCL
note: Copyright © The Author 2021.  Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/).  Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms.  Access may initially be restricted at the author’s request.
abstract: This thesis focuses on using the radio-frequency reflectometry technique for dispersive gate sensing of foundry fabricated silicon nanowire quantum dot devices. I will attempt to answer three questions relating to the scalability of these devices. How do electron and hole spin qubits perform in silicon quantum dots? How do we implement and distribute the placement of dispersive gate sensors in scaled-up quantum dot arrays? And how does a single dopant in the silicon channel affect the gate-defined quantum dot?
First, I investigate the difference between electron and hole quantum dots in an ambipolar nanowire device which successfully demonstrated reconfigurable single and double electron and hole quantum dots in the same crystalline environment. I further investigate the effective bath temperature of two-dimensional electron gas and two-dimensional hole gas by performing the thermometry experiment on the same type of device. Secondly, I demonstrate a two-dimensional quantum dot array
enabled by a floating gate architecture between silicon nanowires. An analytical model is developed to study the capacitive coupling between remote quantum dots over different distances. Coupling strength under different qubit encodings is also discussed to show the best implementation for neighbour silicon nanowires. Finally, the in-situ dispersive gate sensing allows the measurement of the inter-dot transition between the bismuth donor-dot system. The novel implementation with bismuth donor can open up the possibility of a hybrid singlet-triplet qubit or transferring a coherent spin state between the quantum dot and the donor.
date: 2022-10-28
date_type: published
oa_status: green
full_text_type: other
thesis_class: doctoral_open
thesis_award: Ph.D
language: eng
primo: open
primo_central: open_green
verified: verified_manual
elements_id: 1982317
lyricists_name: Duan, Jingyu
lyricists_id: JDUAN23
actors_name: Duan, Jingyu
actors_id: JDUAN23
actors_role: owner
full_text_status: public
pagerange: 1-156
pages: 156
institution: UCL (University College London)
department: Electronic & Electrical Engineering
thesis_type: Doctoral
editors_name: Morton, JOHN
citation:        Duan, Jingyu;      (2022)    Gate-based sensing of silicon quantum dot devices towards 2D scaling.                   Doctoral thesis  (Ph.D), UCL (University College London).     Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/10157370/2/Jingyu_thesis_final.pdf