Transferência de mágnons em cadeias de Heisenberg desordenadas

Detalhes bibliográficos
Ano de defesa: 2023
Autor(a) principal: LIMA, Wilma Valeria Pereira de lattes
Orientador(a): LIMA, Jonas Romero Fonseca de
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal Rural de Pernambuco
Programa de Pós-Graduação: Programa de Pós-Graduação em Física Aplicada
Departamento: Departamento de Física
País: Brasil
Palavras-chave em Português:
Área do conhecimento CNPq:
Link de acesso: http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/9379
Resumo: This work investigates the magnon transference throughout a disordered Heisenberg chain. We considered a model consisting of a source S, site number one, connected to a receiver R, in the last site, using Heisenberg spins. The inner sites work as a channel connecting S and R. In our model, the Heisenberg coupling between nearest-neighbor spins at the channel are random numbers. In addition, we also include an external magnetic field. In our model, the magnetic field is also random numbers uniformly distributed. The coupling between the sites S and R and the inner sites is a tunable parameter called g. Our calculations were done by considering a spin deviation at site number one and obtaining its propagation for long times. Our analyzes indicate that for g much smaller than one e for a weak disorder, it is possible to obtain quantum transfer of magnon from the first to the last site whenever the effective diagonal energies of the first and from the last site are close to the uniform mode, E = 0. We discuss in detail the necessary conditions to maintain this magnon transfer. In particular, we obtained approximately mean maximum values for disorder in internal couplings and field disturbance magnetic, which we can choose to keep good transfer.