Dicke states: production from EPR pairs and entanglement analysis

• Ano de defesa: 2017
• Autor(a) principal: MORENO FILHO, Marcos George Magalhães
• Orientador(a): PARISIO FILHO, Fernando Roberto de Luna
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Pernambuco
• Programa de Pós-Graduação: Programa de Pos Graduacao em Fisica
• País: Brasil
• Palavras-chave em Português: Física quântica; Emaranhamento; Fenômenos críticos; Testemunha de emaranhamento
• Link de acesso: https://repositorio.ufpe.br/handle/123456789/27714

In this work we analyze the problem of creation of Dicke states through the process of entanglement swapping. First we deal with the tripartite case, presenting a deterministic protocol based on a source of EPR pairs. Still in this topic we show that it is possible to create perfect W states (tripartite Dicke states), even when the EPR source does not yield maximally entangled pairs, with a finite success rate. Subsequently we cope with the n-partite case, for which we present a probabilistic procedure, also employing EPR-pair sources, where the output, whenever successful, is perfect. The analysis of this protocol reveals a critical transition for the success probability, which is characterized in the framework of Landau theory of second order phase-transitions. Finally we proceed with a study of the entanglement between bipartitions of systems described by Dicke states, which allows for the implementation of entanglement witnesses. For each Dicke state we present a highly sensitive witness.