Simulação computacional da produção de emaranhamento em ponto quântico caótico não ideal para ensembles de Wigner-Dyson

• Ano de defesa: 2015
• Autor(a) principal: Santos, Eduardo Henrique dos
• Orientador(a): Almeida, Francisco Assis Gois de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Sergipe
• Programa de Pós-Graduação: Pós-Graduação em Física
• País: Brasil
• Palavras-chave em Português: Física; Simulação (Computadores); Emaranhamento quântico; Ponto quântico; Emaranhamento; Simulação numérica
• Palavras-chave em Inglês: Entanglement; Quantum dot; Numerical simulation
• Área do conhecimento CNPq: CIENCIAS EXATAS E DA TERRA::FISICA
• Link de acesso: https://ri.ufs.br/handle/riufs/5368

e recent advances in technology require an increasingly complex treatment from science. Devices intensely miniaturized especially cannot be treated with classical physics only. e quantum approach becomes essential when the size of the conductors reaches the order of the electron characteristic lengths. Systems in this regime exhibit some important features, such as quantum interference and quantization of some quantities, and are named mesoscopic systems. Entanglement is a property with large technological applicability and can only be explained with the quantum approach. e quantum dot is very useful as mesoscopic entangler of electrons. e electron transport in a quantum dot can be described by the scattering matrix. e transmission eigenvalues obtained from the scattering matrix provide some quantities related to the electron transport, including the quanti er of entanglement. In this work we study statistically the entanglement production in a chaotic quantum dot (CCD) with nonideal contacts. ese CCDs are modeled as scattering centers attached to two wave guides having potential barriers and the electron transport is described by random scattering matrices.We consider time reversal and spin rotation symmetries for the cavities so that the scattering matrices belong to theWigner-Dyson ensembles. e concurrence was used for quantifying entanglement and was also statistically investigated. Similarly, we analyse the squared norm which is also dependent of the transmission eigenvalues and represents the probability of the scatterings result in an entangled state.We de ne the entanglement production factor for determining more precisely the e ciency of the entangler. We used a third-party algorithm to generate the scattering matrices and then we found the transmission eigenvalues for each matrix.We computed the averages of concurrence, squared norm and entanglement production factor and generated some of their distribution curves varying the opacities of the leads.