Generalized entanglement in quantum information theory : optimization free measures and faithful extraction protocols

• Main Author: Κόλλας, Νικόλαος
• Other Authors: Αναστόπουλος, Χάρης
• Format: Thesis
• Language: English
• Published: 2020
• Subjects: Quantum information; Quantum resource theories; Κβαντική πληροφορία; Κβαντική θεωρία πόρων; Μέτρα πόρων; Πρωτόκολλα εξαγωγής; 530.124

By studying generalizations of entanglement to quantum resource theories,we will provide a continuous family of optimization free measures to quantify the resource in a system, for any theory whose set of free states is given by the image of an idempotent and unital quantum operation. With the help of these measures we will argue for the correct definition of a coarse grained projective quantum measurement. The question of extraction of quantum coherence from one system to another in a faithful way is also studied. We construct two novel protocols, one able to extract only a small amount of coherence each time and the other a larger amount and apply these to a reservoir in a coherent and vacuum squeezed state of a harmonic oscillator. By studying extraction to qubits it is shown that for a single extraction from both reservoirs the stronger protocol outperforms a previous method known as catalytic coherence.