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Quantum network coding
Thesis (MSc)--Stellenbosch University, 2022.
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| Format: | Thesis |
| Language: | en_ZA |
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Stellenbosch : Stellenbosch University
2022
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| _version_ | 1867614044691628032 |
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| access_status_str | Open Access |
| author | Rall, Hjalmar |
| author2 | Tame, M. S. |
| author_browse | Rall, Hjalmar Tame, M. S. |
| author_facet | Tame, M. S. Rall, Hjalmar |
| author_sort | Rall, Hjalmar |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MSc)--Stellenbosch University, 2022. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/126304 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:45:46.810Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2022 |
| publishDateRange | 2022 |
| publishDateSort | 2022 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/126304 Quantum network coding Rall, Hjalmar Tame, M. S. Stellenbosch University. Faculty of Science. Dept. of Physics. Quantum communication -- Data processing Coding theory Quantum computing -- Measurement Quantum teleportation UCTD Thesis (MSc)--Stellenbosch University, 2022. ENGLISH ABSTRACT: Communication takes place at every level in the processing of information, from the trans- porting of individual bits between logic gates in a classical computer to large transfers of data between computers over the internet. The study of communication is therefore essential to understanding information processing and particularly so in the case of quantum information processing. Quantum communication enables interactions between distant quantum systems and as such plays a key role in important applications of quantum information, such as distributed quantum computing, quantum key distribution, and information transport within quantum processors. Recent years have seen the introduction of noisy intermediate-scale quantum (NISQ) processors with upward of 100 qubits capable of performing simple quantum algo- rithms, as well as quantum communication networks achieving high fidelity. Despite the im- provements in the hardware, noise and limited resources remain a hurdle to effective quantum communication. This is of particular practical importance in the scenario where multiple par- ties must simultaneously communicate quantum information across a shared quantum net- work, such as a future quantum internet. In this thesis, I study quantum network coding (QNC) and specifically the derivative measurement-based quantum network coding (MQNC), an alternative to standard quantum information routing, which promises reduced noise and resource requirements. By redistributing entanglement in resources called graph states, I was able to implement MQNC on current generation IBM Q superconducting quantum processors based in York- town Heights in New York State and subsequently performed the protocol with improved fidelity compared to that which could be achieved using an earlier iteration of the hardware. Starting from these improved experimental results, noise in MQNC was studied in the con- text of a NISQ processor. While still noisy, the final states generated using MQNC possessed some entanglement useful for communication, and the conditions under which teleportation is possible across these states were investigated. The possibility of entanglement purification for further reduction of noise was also investigated, but was not found to be practical on the current IBM hardware. Additionally, I introduce an alternative interpretation of QNC in the context of network switching and develop an efficient n × n non-blocking switch based on MQNC and a clas- sical switch network. This switch has a number of favourable properties in the context of NISQ hardware and may be implemented directly on a common processor topology. Lastly, protection against qubit loss errors tailored to MQNC was studied in the form of substantial modifications to a previously introduced counterfactual loss tolerance scheme. AFRIKAANSE OPSOMMING: Kommunikasie vind plaas op elke vlak van die verwerking van inligting, van die verskuiwing van individuële bisse tussen logikahekke in ’n klassieke rekenaar tot die oordra van groot hoe- veelhede data tussen rekenaars oor die internet. Die studie van kommunikasie is dus nood- saaklik vir die verstaan van inligtingsverwerking, en dit is veral so in die geval van kwantum- inligtingsverwerking. Kwantumkommunikasie maak interaksies tussen verafgeleë kwantumstelsels moontlik en speel dus ’n sleutelrol in belangrike toepassings van kwantuminligting soos verspreide kwan- tumberekening, kwantumsleutelverspreiding en inligtingvervoer binne kwantumverwerkers. In die afgelope paar jaar is ruisende intermediêre skaal kwantum (NISQ) verwerkers ontwik- kel wat opwaarts van 100 kwabisse beskik en in staat is om eenvoudige kwantumalgoritmes uit te voer. Daar is ook kwantumkommunikasienetwerke bekendgestel wat hoë getrouheid bereik. Ten spyte van die verbeterings in kwantumhardeware, bly geruis en beperkte hulpbronne ’n hindernis vir effektiewe kwantumkommunikasie. Hierdie is van besondere praktiese belang in gevalle waar verskeie partye gelyktydig kwantuminligting oor ’n gedeelde kwantumnetwerk moet stuur, soos byvoorbeeld in ’n toekomstige kwantuminternet. In hierdie tesis bestudeer ek kwantumnetwerkkodering (QNC) en spesifiek die afgelei- de waarneming-gebaseerde kwantumnetwerkkodering (MQNC), ’n alternatief tot standaard kwantuminligtingroetering wat dui op goeie vooruitsigte vir vermindering van geruis en hulp- bronvereistes. Deur verstrengeling in grafiektoestande te herversprei, kon ek MQNC uitvoer op huidi- ge generasie IBM Q supergeleidende kwantumverwerkers gebaseer in Yorktown Heights in New York Staat. Die getrouheid aan die teikenresultate was nader as wat haalbaar was met ’n vroëre weergawe van die verwerkers. Gebaseer op hierdie verbeterde eksperimentele resultate is geruis in MQNC bestudeer in die konteks van ’n NISQ-verwerker. Terwyl hulle nog rui- serig was, het die finale toestande wat met MQNC gegenereer is ’n mate van verstrengeling gehad wat nuttig is vir kommunikasie. Die toestande waaronder teleportasie oor hierdie toe- stande moontlik is is ondersoek. Die moontlikheid van verstrengelingssuiwering vir verdere vermindering van geruis is ook ondersoek, maar dit was nie prakties bevind op die huidige IBM verwerkerhardeware nie. Ek lê ook ’n alternatiewe interpretasie van QNC in die konteks van netwerkskakeling voor, en ontwikkel ’n doeltreffende n×n nie-blokkerende netwerkskakelaar gebaseer op MQNC en ’n klassieke skakelaarnetwerk. Hierdie skakelaar het ’n aantal gunstige eienskappe in die kon- teks van NISQ-hardeware en kan direk op ’n algemene verwerkertopologie geïmplementeer word. Laastens bestudeer ek beskerming teen kwabisverliesfoute aangepas vir MQNC. Die is in die vorm van aansienlike wysigings aan ’n kontrafeitelike verliesweerstandskema wat voor- heen bekendgestel was. Masters 2022-11-02T10:57:46Z 2023-01-23T06:51:19Z 2022-11-02T10:57:46Z 2022-12 Thesis http://hdl.handle.net/10019.1/126304 en_ZA Stellenbosch University xvi, 145 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Quantum communication -- Data processing Coding theory Quantum computing -- Measurement Quantum teleportation UCTD Rall, Hjalmar Quantum network coding |
| title | Quantum network coding |
| title_full | Quantum network coding |
| title_fullStr | Quantum network coding |
| title_full_unstemmed | Quantum network coding |
| title_short | Quantum network coding |
| title_sort | quantum network coding |
| topic | Quantum communication -- Data processing Coding theory Quantum computing -- Measurement Quantum teleportation UCTD |
| url | http://hdl.handle.net/10019.1/126304 |
| work_keys_str_mv | AT rallhjalmar quantumnetworkcoding |