Dinâmica de mágnons na presença de defeito topológico
Autor(a) principal: | |
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Data de Publicação: | 2018 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Biblioteca Digital de Teses e Dissertações da UFPB |
Texto Completo: | https://repositorio.ufpb.br/jspui/handle/123456789/15329 |
Resumo: | "The advent of Quantum Mechanics brought a new understanding of the world and new perspectives of technology, such as methods of optimization and alternatives to classical electronics. Recently an alternative has been sought for conventional electronics based on the electric current, this electronics would be based on spin propagations, and therefore we call it spintronics. In view of this perspective, the study of spin waves and magnetic phenomena in solid state physics is of paramount importance. Therefore, we have studied Magnons from the quantum Hall effect and sought the dynamics of these quasi particles subjected to a topological defect. In this work we will review the Aharonov-Bohm and Aharonov-Casher Effect to understand the quantum phases as geometric phases. We will study the Berry phase as the result of an external influence and Berry’s curvature to then verify the occurrence of the Quantum Hall effect. We sought the quantization of Landau for neutral particles with magnetic and electric dipole moment subjected to external electromagnetic fields. We sought to conceptualize magnons as collective low energy excitations and look for the occurrence of Hall Effect for them through the quantization of the Transverse Hall conductance. We also look for the Thermal Hall conductance due to a temperature gradient and thus the thermomagnetic ratio, we observe that such a reason follows Wiedemann-Franz’s law. We also review the Landau quantization for a neutral particle with a magnetic dipole moment and subjected to a topological defect of the cosmic string type and verify that the presence of the defect breaks the infinite degeneration of the Landau levels. In this work we consider the Hamiltonian proposed by Bakke, Ribeiro, Furtado and Nascimento (2009) [25] as the effective hamiltonian of the magnons in the presence of topological defect of the type cosmic string and we find the levels of Landau for the system. With this, it was possible to find preliminary results of Hall and Hall Thermal conductance of magnons in the curved space of the cosmic string at the non-relativistic and low temperature limits. Studying the properties of a network of magnons this work also seeks to instigate research that seeks to understand the behavior of the properties of these quasi-particles subjected to topological defects of various types and thus contribute to a better understanding of the dynamics of magnons and their properties." |
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Dinâmica de mágnons na presença de defeito topológicoMágnonsDefeitoTopológicoEfeito Hall QuânticoCondutânciaQuantização de LandauTopological DefectQuantum Hall EffectConductanceLandau QuantizationFases quânticasCNPQ::CIENCIAS EXATAS E DA TERRA::FISICA"The advent of Quantum Mechanics brought a new understanding of the world and new perspectives of technology, such as methods of optimization and alternatives to classical electronics. Recently an alternative has been sought for conventional electronics based on the electric current, this electronics would be based on spin propagations, and therefore we call it spintronics. In view of this perspective, the study of spin waves and magnetic phenomena in solid state physics is of paramount importance. Therefore, we have studied Magnons from the quantum Hall effect and sought the dynamics of these quasi particles subjected to a topological defect. In this work we will review the Aharonov-Bohm and Aharonov-Casher Effect to understand the quantum phases as geometric phases. We will study the Berry phase as the result of an external influence and Berry’s curvature to then verify the occurrence of the Quantum Hall effect. We sought the quantization of Landau for neutral particles with magnetic and electric dipole moment subjected to external electromagnetic fields. We sought to conceptualize magnons as collective low energy excitations and look for the occurrence of Hall Effect for them through the quantization of the Transverse Hall conductance. We also look for the Thermal Hall conductance due to a temperature gradient and thus the thermomagnetic ratio, we observe that such a reason follows Wiedemann-Franz’s law. We also review the Landau quantization for a neutral particle with a magnetic dipole moment and subjected to a topological defect of the cosmic string type and verify that the presence of the defect breaks the infinite degeneration of the Landau levels. In this work we consider the Hamiltonian proposed by Bakke, Ribeiro, Furtado and Nascimento (2009) [25] as the effective hamiltonian of the magnons in the presence of topological defect of the type cosmic string and we find the levels of Landau for the system. With this, it was possible to find preliminary results of Hall and Hall Thermal conductance of magnons in the curved space of the cosmic string at the non-relativistic and low temperature limits. Studying the properties of a network of magnons this work also seeks to instigate research that seeks to understand the behavior of the properties of these quasi-particles subjected to topological defects of various types and thus contribute to a better understanding of the dynamics of magnons and their properties."Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq"O advento da Mecânica Quântica trouxe uma nova compreensão de mundo e novas perspectivas de tecnologia, tais como métodos de otimização e alternativas à eletrônica clássica. Recentemente vem sendo buscada uma alternativa a eletrônica convencional pautada na corrente de elétrica, essa eletrônica teria como base as propagações de spin, e portanto a chamamos de spintrônica. Tendo em vista tal perspectiva, é de suma importância o estudo de ondas de spin e dos fenômenos magnéticos em física do estado sólido. Portanto buscamos aqui estudar mágnons sob a ótica do efeito Hall Quântico e buscar a dinâmica dessas quase-partículas submetidas a um defeito topológico. Nesse trabalho vamos fazer uma revisão do Efeito Aharonov-Bohm e Aharonov-Casher para entender as fases quânticas como fases geométricas. Vamos estudar a fase de Berry como o resultado de uma influência externa e a curvatura de Berry para então verificar a ocorrência do efeito Hall Quântico. Procuramos a quantização de Landau para partículas neutras com momento de dipolo magnético e elétrico sujeitas a campos eletromagnéticos externos. Buscamos conceituar mágnons como excitações coletivas de baixa energia e procuramos a ocorrência de Efeito Hall para estes através da quantização da condutância Hall Transversal. Buscamos também a condutância Hall Térmica devido um gradiente de temperatura e assim a razão termomagnética, observamos que tal razão segue a lei de Wiedemann-Franz. Revisamos também a quantização de Landau para uma partícula neutra com momento de dipolo magnético e submetida a um defeito topológico do tipo corda cósmica e verificamos que a presença do defeito quebra a degenerescência infinita dos níveis de Landau. Nesse trabalho consideramos o hamiltoniano proposto por Bakke, Ribeiro, Furtado e Nascimento (2009) [25] como o hamiltoniano efetivo dos mágnons na presença de defeito topológico do tipo corda cósmica e encontramos os níveis de Landau para o sistema. Com isso foi possível encontrar resultados preliminares da condutância Hall e Hall Térmica de mágnons no espaço curvo da corda cósmica no limite não relativístico e de baixas temperaturas. Estudando as propriedades de uma rede de mágnons esse trabalho busca também instigar a pesquisa que visa entender o comportamento das propriedades dessas quase partículas sujeitas a defeitos topológicos de vários tipos e contribuir assim para o melhor entendi mento da dinâmica de mágnons e de suas propriedades."Universidade Federal da ParaíbaBrasilFísicaPrograma de Pós-Graduação em FísicaUFPBFurtado, Cláudio Benedito Silvahttp://lattes.cnpq.br/9364148865735922Silva, Daniel Borges2019-08-21T12:28:58Z2019-02-142019-08-21T12:28:58Z2018-12-19info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesishttps://repositorio.ufpb.br/jspui/handle/123456789/15329porAttribution-NoDerivs 3.0 Brazilhttp://creativecommons.org/licenses/by-nd/3.0/br/info:eu-repo/semantics/openAccessreponame:Biblioteca Digital de Teses e Dissertações da UFPBinstname:Universidade Federal da Paraíba (UFPB)instacron:UFPB2019-08-22T06:06:27Zoai:repositorio.ufpb.br:123456789/15329Biblioteca Digital de Teses e Dissertaçõeshttps://repositorio.ufpb.br/PUBhttp://tede.biblioteca.ufpb.br:8080/oai/requestdiretoria@ufpb.br|| diretoria@ufpb.bropendoar:2019-08-22T06:06:27Biblioteca Digital de Teses e Dissertações da UFPB - Universidade Federal da Paraíba (UFPB)false |
dc.title.none.fl_str_mv |
Dinâmica de mágnons na presença de defeito topológico |
title |
Dinâmica de mágnons na presença de defeito topológico |
spellingShingle |
Dinâmica de mágnons na presença de defeito topológico Silva, Daniel Borges Mágnons DefeitoTopológico Efeito Hall Quântico Condutância Quantização de Landau Topological Defect Quantum Hall Effect Conductance Landau Quantization Fases quânticas CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA |
title_short |
Dinâmica de mágnons na presença de defeito topológico |
title_full |
Dinâmica de mágnons na presença de defeito topológico |
title_fullStr |
Dinâmica de mágnons na presença de defeito topológico |
title_full_unstemmed |
Dinâmica de mágnons na presença de defeito topológico |
title_sort |
Dinâmica de mágnons na presença de defeito topológico |
author |
Silva, Daniel Borges |
author_facet |
Silva, Daniel Borges |
author_role |
author |
dc.contributor.none.fl_str_mv |
Furtado, Cláudio Benedito Silva http://lattes.cnpq.br/9364148865735922 |
dc.contributor.author.fl_str_mv |
Silva, Daniel Borges |
dc.subject.por.fl_str_mv |
Mágnons DefeitoTopológico Efeito Hall Quântico Condutância Quantização de Landau Topological Defect Quantum Hall Effect Conductance Landau Quantization Fases quânticas CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA |
topic |
Mágnons DefeitoTopológico Efeito Hall Quântico Condutância Quantização de Landau Topological Defect Quantum Hall Effect Conductance Landau Quantization Fases quânticas CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA |
description |
"The advent of Quantum Mechanics brought a new understanding of the world and new perspectives of technology, such as methods of optimization and alternatives to classical electronics. Recently an alternative has been sought for conventional electronics based on the electric current, this electronics would be based on spin propagations, and therefore we call it spintronics. In view of this perspective, the study of spin waves and magnetic phenomena in solid state physics is of paramount importance. Therefore, we have studied Magnons from the quantum Hall effect and sought the dynamics of these quasi particles subjected to a topological defect. In this work we will review the Aharonov-Bohm and Aharonov-Casher Effect to understand the quantum phases as geometric phases. We will study the Berry phase as the result of an external influence and Berry’s curvature to then verify the occurrence of the Quantum Hall effect. We sought the quantization of Landau for neutral particles with magnetic and electric dipole moment subjected to external electromagnetic fields. We sought to conceptualize magnons as collective low energy excitations and look for the occurrence of Hall Effect for them through the quantization of the Transverse Hall conductance. We also look for the Thermal Hall conductance due to a temperature gradient and thus the thermomagnetic ratio, we observe that such a reason follows Wiedemann-Franz’s law. We also review the Landau quantization for a neutral particle with a magnetic dipole moment and subjected to a topological defect of the cosmic string type and verify that the presence of the defect breaks the infinite degeneration of the Landau levels. In this work we consider the Hamiltonian proposed by Bakke, Ribeiro, Furtado and Nascimento (2009) [25] as the effective hamiltonian of the magnons in the presence of topological defect of the type cosmic string and we find the levels of Landau for the system. With this, it was possible to find preliminary results of Hall and Hall Thermal conductance of magnons in the curved space of the cosmic string at the non-relativistic and low temperature limits. Studying the properties of a network of magnons this work also seeks to instigate research that seeks to understand the behavior of the properties of these quasi-particles subjected to topological defects of various types and thus contribute to a better understanding of the dynamics of magnons and their properties." |
publishDate |
2018 |
dc.date.none.fl_str_mv |
2018-12-19 2019-08-21T12:28:58Z 2019-02-14 2019-08-21T12:28:58Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
https://repositorio.ufpb.br/jspui/handle/123456789/15329 |
url |
https://repositorio.ufpb.br/jspui/handle/123456789/15329 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.rights.driver.fl_str_mv |
Attribution-NoDerivs 3.0 Brazil http://creativecommons.org/licenses/by-nd/3.0/br/ info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
Attribution-NoDerivs 3.0 Brazil http://creativecommons.org/licenses/by-nd/3.0/br/ |
eu_rights_str_mv |
openAccess |
dc.publisher.none.fl_str_mv |
Universidade Federal da Paraíba Brasil Física Programa de Pós-Graduação em Física UFPB |
publisher.none.fl_str_mv |
Universidade Federal da Paraíba Brasil Física Programa de Pós-Graduação em Física UFPB |
dc.source.none.fl_str_mv |
reponame:Biblioteca Digital de Teses e Dissertações da UFPB instname:Universidade Federal da Paraíba (UFPB) instacron:UFPB |
instname_str |
Universidade Federal da Paraíba (UFPB) |
instacron_str |
UFPB |
institution |
UFPB |
reponame_str |
Biblioteca Digital de Teses e Dissertações da UFPB |
collection |
Biblioteca Digital de Teses e Dissertações da UFPB |
repository.name.fl_str_mv |
Biblioteca Digital de Teses e Dissertações da UFPB - Universidade Federal da Paraíba (UFPB) |
repository.mail.fl_str_mv |
diretoria@ufpb.br|| diretoria@ufpb.br |
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1801842952105885696 |