Collective and intrinsic degrees of freedom in the Heisenberg ferromagnet.

Detalhes bibliográficos
Autor(a) principal: Providência, João da
Data de Publicação: 1989
Outros Autores: Brajczewska, Marta, Fiolhais, Carlos
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/10316/40857
https://doi.org/10.1088/0305-4470/22/6/021
Resumo: A separation between collective and intrinsic degrees of freedom in the Heisenberg model of a ferromagnet at a finite temperature is achieved by reformulating the thermal boson expansion previously obtained by the present authors. In the new approach, all the collective modes (spin waves) have wavenumbers lower than a certain value. The intrinsic energy turns out to be the usual mean-field energy minus a correlation energy due to the excitations of spin waves. The influence of the cutoff in momentum space on the critical temperature is studied and the temperature dependence of the spin-wave renormalisation factor and the magnetisation are calculated.
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spelling Collective and intrinsic degrees of freedom in the Heisenberg ferromagnet.Heisenberg ferromagnetA separation between collective and intrinsic degrees of freedom in the Heisenberg model of a ferromagnet at a finite temperature is achieved by reformulating the thermal boson expansion previously obtained by the present authors. In the new approach, all the collective modes (spin waves) have wavenumbers lower than a certain value. The intrinsic energy turns out to be the usual mean-field energy minus a correlation energy due to the excitations of spin waves. The influence of the cutoff in momentum space on the critical temperature is studied and the temperature dependence of the spin-wave renormalisation factor and the magnetisation are calculated.Institute of Physics1989info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://hdl.handle.net/10316/40857http://hdl.handle.net/10316/40857https://doi.org/10.1088/0305-4470/22/6/021engPROVIDÊNCIA, João da ; BRAJCZEWSKA, Marta ; FIOLHAIS, Carlos – Collective and intrinsic degrees of freedom in the Heisenberg ferromagnet. Journal of physics. A : Mathematical and Theoretical. Bristol : Institute of Physics. ISSN 1751-8113. Vol. 22 (1989), p. 703-715.1751-8113Providência, João daBrajczewska, MartaFiolhais, Carlosinfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2020-05-29T09:42:13Zoai:estudogeral.uc.pt:10316/40857Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T20:59:58.461208Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse
dc.title.none.fl_str_mv Collective and intrinsic degrees of freedom in the Heisenberg ferromagnet.
title Collective and intrinsic degrees of freedom in the Heisenberg ferromagnet.
spellingShingle Collective and intrinsic degrees of freedom in the Heisenberg ferromagnet.
Providência, João da
Heisenberg ferromagnet
title_short Collective and intrinsic degrees of freedom in the Heisenberg ferromagnet.
title_full Collective and intrinsic degrees of freedom in the Heisenberg ferromagnet.
title_fullStr Collective and intrinsic degrees of freedom in the Heisenberg ferromagnet.
title_full_unstemmed Collective and intrinsic degrees of freedom in the Heisenberg ferromagnet.
title_sort Collective and intrinsic degrees of freedom in the Heisenberg ferromagnet.
author Providência, João da
author_facet Providência, João da
Brajczewska, Marta
Fiolhais, Carlos
author_role author
author2 Brajczewska, Marta
Fiolhais, Carlos
author2_role author
author
dc.contributor.author.fl_str_mv Providência, João da
Brajczewska, Marta
Fiolhais, Carlos
dc.subject.por.fl_str_mv Heisenberg ferromagnet
topic Heisenberg ferromagnet
description A separation between collective and intrinsic degrees of freedom in the Heisenberg model of a ferromagnet at a finite temperature is achieved by reformulating the thermal boson expansion previously obtained by the present authors. In the new approach, all the collective modes (spin waves) have wavenumbers lower than a certain value. The intrinsic energy turns out to be the usual mean-field energy minus a correlation energy due to the excitations of spin waves. The influence of the cutoff in momentum space on the critical temperature is studied and the temperature dependence of the spin-wave renormalisation factor and the magnetisation are calculated.
publishDate 1989
dc.date.none.fl_str_mv 1989
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://hdl.handle.net/10316/40857
http://hdl.handle.net/10316/40857
https://doi.org/10.1088/0305-4470/22/6/021
url http://hdl.handle.net/10316/40857
https://doi.org/10.1088/0305-4470/22/6/021
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv PROVIDÊNCIA, João da ; BRAJCZEWSKA, Marta ; FIOLHAIS, Carlos – Collective and intrinsic degrees of freedom in the Heisenberg ferromagnet. Journal of physics. A : Mathematical and Theoretical. Bristol : Institute of Physics. ISSN 1751-8113. Vol. 22 (1989), p. 703-715.
1751-8113
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.publisher.none.fl_str_mv Institute of Physics
publisher.none.fl_str_mv Institute of Physics
dc.source.none.fl_str_mv reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
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reponame_str Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
collection Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
repository.name.fl_str_mv Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
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