Quantum superposition as a resource for quantum communication

master's thesis

• Title (croatian): Kvantna superpozicija kao resurs za kvantnu komunikaciju
• Author: Sebastian Horvat
• Mentor: Borivoje Dakić (mentor)
• Mentor: Krešimir Kumerički (mentor)
• Committee member: Krešimir Kumerički (predsjednik povjerenstva)
• Committee member: Borivoje Dakić (član povjerenstva)
• Committee member: Nikola Poljak (član povjerenstva)
• Committee member: Ivica Smolić (član povjerenstva)
• Committee member: Petar Žugec (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Physics); Zagreb
• Defense date and country: 2019-12-09, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract

Glavni cilj ovog rada je istraživanje prostorne superpozicije u kontekstu kvantne komunikacije. U klasičnoj fizici, u svakom vremenskom trenutku, informacija teče maksimalno u jednom smjeru, odnosno prenosioci informacija prenose poruku od pošiljatelja ka primatelju, ali ne i obratno. S druge strane, kvantna fizika otvara nove mogućnosti dozvoljavajući prostornu superpoziciju fizikalnih sustava što omogućava dvosmjerni prijenos informacija (od pošiljatelja ka primatelju i obratno). Naš cilj je doći do novih komunikacijskih procesa koje nije moguće implementirati u klasičnoj mehanici te stoga kvantificirati prostornu superpoziciju kao resurs za komunikaciju. Preciznije, cilj nam je klasificirati jednostavne komunikacijske protokole (npr. protokole koji uključuju izmjenu informacija između nekoliko igrača, s restrikcijom na resurse) putem analogona Bellovih nejednakosti. S druge strane, klasifikacija takvih nejednakosti pruža prirodnu operativnu metodu kojom se može pokazati da kvantni prenosioci informacija istinski predstavljaju resurs za ne-klasičnu komunikaciju (eksplicitnim narušenjem spomenutih nejednakosti).

Abstract (english)

The main objective of this thesis is to explore spatial superposition as a novel resource for quantum communication. In classical physics, at any instant of time, information flows in one direction only, i.e. an information carrier transmits the message from the sender to the receiver, but not vice versa. In contrast, quantum physics opens up the possibility of putting information carriers in spatial superposition which in turn enables simultaneous bi-directional transmission of information between the sender and the receiver. Our aim is explore this possibility to arrive at new communication tasks that cannot be accomplished within classical physics, thus quantifying the use of quantum superposition as a resource for communication. More precisely, we aim at classifying simple communication protocols (e.g. involving the exchange of information between several players, with restrictions on the available resources) by means of Bell-like inequalities, which set precise limits to classical communication. On the other hand, the classification of these inequalities provides a natural operational framework to show that quantum information carriers in spatial superposition are a genuine resource for non-classical communication (i.e. by explicitly violating the bounds imposed by Bell-like inequalities).

• Keywords: prostorna superpozicija; kvantna komunikacija; Bellove nejednakosti; konveksna geometrija; ”device-independent” formalizam; teorije
• Keywords (english): spatial superposition; quantum communication; Bell’s inequalities; convex geometry; device-independent formalism; higher order
• Language: english
• URN:NBN: urn:nbn:hr:217:638859
• Study programme: Title: Physics; specializations in: Research; Course: Research; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra fizike (magistar/magistra fizike)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-01-07 12:28:03