Sökning: "device-independent"

Visar resultat 1 - 5 av 16 avhandlingar innehållade ordet device-independent.

1. 1. Photonic multipartite entanglement : Generation, measurement and applications

   Författare :Massimiliano Smania; Mohamed Bourennane; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum information; entanglement; Bell tests; POVM; device-independent; self-testing; quantum optics; prepare-and-measure; fysik; Physics;

   Sammanfattning : We are currently witnessing a fundamental change in the field of quantum information, whereby protocols and experiments previously performed in university labs are now being implemented in real-world scenarios, and a strong commercial push for new and reliable applications is contributing significantly in advancing fundamental research. In this thesis and related included papers, I first look at a keystone of quantum science, Bell's theorem. LÄS MER

3. 2. Exploring the Elegant Bell Inequality

   Författare :Irina Dumitru; Ingemar Bengtsson; Marcin Pawłowski; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bell inequality; Symmetric Informationally Complete POVM; Device Independent Certification; teoretisk fysik; Theoretical Physics;

   Sammanfattning : In quantum information, device independent certification is a matter of both practical and fundamental interest. In this thesis, we explore the use of a particular Bell inequality, known as the elegant Bell inequality, in device independent certification. LÄS MER

4. 3. Studies in the Geometry of Quantum Measurements

   Författare :Irina Dumitru; Ingemar Bengtsson; David Gross; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; quantum measurements; Bell nequalities; Weyl-Heiseberg group; device-independent certification; symmetric informationally-complete POVM; teoretisk fysik; Theoretical Physics;

   Sammanfattning : Quantum information studies quantum systems from the perspective of information theory: how much information can be stored in them, how much the information can be compressed, how it can be transmitted. Symmetric informationally-Complete POVMs are measurements that are well-suited for reading out the information in a system; they can be used to reconstruct the state of a quantum system without ambiguity and with minimum redundancy. LÄS MER

5. 4. Multiparty Quantum Communication and fs-laser Written Integrated Optics Circuits

   Författare :Ashraf Mohamed El Hassan; Mohamed Bourennane; Guillermo Andler; Marcos Curty; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Quantum optics; quantum communication; quantum cryptography; fs-laser written waveguides; integrated optics circuits; Physics; fysik;

   Sammanfattning : Quantum information science, the rapidly developing interdisciplinary field,  gives power to the information and communications technologies (ICT) by  providing secure communication, precision measurements, ultra-powerful simulation and ultimately computation. It is well known that photons are an ideal candidate for encoding the quantum bit, or "qubit", in quantum information and specially for quantum communication. LÄS MER

7. 5. Breaking the Unbreakable : Exploiting Loopholes in Bell’s Theorem to Hack Quantum Cryptography

   Författare :Jonathan Jogenfors; Jan-Åke Larsson; Fredrik Karlsson; Marek Żukowski; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : In this thesis we study device-independent quantum key distribution based on energy-time entanglement. This is a method for cryptography that promises not only perfect secrecy, but also to be a practical method for quantum key distribution thanks to the reduced complexity when compared to other quantum key distribution protocols. LÄS MER