Quantum correlations and quantum coherence in open quantum systems

• Ano de defesa: 2018
• Autor(a) principal: Obando, Paola Andrea Concho
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Niterói
• Palavras-chave em Português: Decoherence; Open system; Quantum statistical methods; Quantum information; Entanglement and quantum nonlocality; Mechanical instruments and equipment; Decoherence, open systems; Decoerência; Sistemas abertos; Métodos de estatística quântica; Informação quântica; Emaranhamento e não-localidade quântica; Instrumentos e equipamentos mecânicos
• Link de acesso: https://app.uff.br/riuff/handle/1/7415

In this thesis, methods for the study of open quantum systems are developed and different aspects of Markovian and non-Markovian dynamics are analyzed. The first part of the thesis is devoted to the theoretical foundations of open quantum systems and a brief review of quantum correlations, emphasizing geometric quantum correlations. In the second part of the thesis, we present our main results. More specifically, we firstly provide analytical expressions for classical and total trace-norm (Schatten 1-norm) geometric correlations in the case of two-qubit X states. As an application, we consider the open-system dynamical behavior of such correlations under phase and generalized amplitude damping evolutions. Then, we show that geometric classical correlations can characterize the emergence of the pointer basis of an apparatus subject to decoherence in either Markovian or non-Markovian regimes. Secondly, we provide a characterization of memory effects in non-Markovian system-bath interactions from a quantum information perspective. In particular, we establish sufficient conditions for which generalized measures of multipartite quantum, classical, and total correlations can be used to quantify the degree of non-Markovianity of a local quantum decohering process. We illustrate our results by considering the dynamical behavior of the trace-distance correlations in multi-qubit systems under local dephasing and generalized amplitude damping. Finally, we investigate quantum coherence, discussing its connections with quantum correlations measurements and proposing it as a quantifier of non-Markovianity. As an example, the coherence of a qubit under non-Markovian amplitude damping is analytically discussed.