Qualitative breakdown of the noncrossing approximation for the symmetric one-channel Anderson impurity model at all temperatures

Autores
Sposetti, Cintia Natalia; Manuel, Luis Oscar; Roura Bas, Pablo Gines
Año de publicación
2016
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
The Anderson impurity model is studied by means of the self-consistent hybridization expansions in its noncrossing (NCA) and one-crossing (OCA) approximations. We have found that for the one-channel spin-1/2 particle-hole symmetric Anderson model, the NCA results are qualitatively wrong for any temperature, even when the approximation gives the exact threshold exponents of the ionic states. Actually, the NCA solution describes an overscreened Kondo effect, because it is the same as for the two-channel infinite-U single-level Anderson model. We explicitly show that the NCA is unable to distinguish between these two very different physical systems, independently of temperature. Using the impurity entropy as an example, we show that the low-temperature values of the NCA entropy for the symmetric case yield the limit Simp(T=0)→ln2, which corresponds to the zero temperature entropy of the overscreened Kondo model. Similar pathologies are predicted for any other thermodynamic property. On the other hand, we have found that the OCA approach lifts the artificial mapping between the models and restores correct properties of the ground state, for instance, a vanishing entropy at low enough temperatures Simp(T=0)→0. Our results indicate that the very well known NCA should be used with caution close to the symmetric point of the Anderson model.
Fil: Sposetti, Cintia Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; Argentina
Fil: Manuel, Luis Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; Argentina
Fil: Roura Bas, Pablo Gines. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina
Materia
KONDO EFFECT
ANDERSON MODEL
NON CROSSING APPROXIMATION
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/50749
Acceder
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network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Qualitative breakdown of the noncrossing approximation for the symmetric one-channel Anderson impurity model at all temperaturesSposetti, Cintia NataliaManuel, Luis OscarRoura Bas, Pablo GinesKONDO EFFECTANDERSON MODELNON CROSSING APPROXIMATIONhttps://purl.org/becyt/ford/1.3https://purl.org/becyt/ford/1The Anderson impurity model is studied by means of the self-consistent hybridization expansions in its noncrossing (NCA) and one-crossing (OCA) approximations. We have found that for the one-channel spin-1/2 particle-hole symmetric Anderson model, the NCA results are qualitatively wrong for any temperature, even when the approximation gives the exact threshold exponents of the ionic states. Actually, the NCA solution describes an overscreened Kondo effect, because it is the same as for the two-channel infinite-U single-level Anderson model. We explicitly show that the NCA is unable to distinguish between these two very different physical systems, independently of temperature. Using the impurity entropy as an example, we show that the low-temperature values of the NCA entropy for the symmetric case yield the limit Simp(T=0)→ln2, which corresponds to the zero temperature entropy of the overscreened Kondo model. Similar pathologies are predicted for any other thermodynamic property. On the other hand, we have found that the OCA approach lifts the artificial mapping between the models and restores correct properties of the ground state, for instance, a vanishing entropy at low enough temperatures Simp(T=0)→0. Our results indicate that the very well known NCA should be used with caution close to the symmetric point of the Anderson model.Fil: Sposetti, Cintia Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Manuel, Luis Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Roura Bas, Pablo Gines. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; ArgentinaAmerican Physical Society2016-08info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/50749Sposetti, Cintia Natalia; Manuel, Luis Oscar; Roura Bas, Pablo Gines; Qualitative breakdown of the noncrossing approximation for the symmetric one-channel Anderson impurity model at all temperatures; American Physical Society; Physical Review B: Condensed Matter and Materials Physics; 94; 8; 8-2016; 851391-8513981098-01212469-9969CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/https://journals.aps.org/prb/abstract/10.1103/PhysRevB.94.085139info:eu-repo/semantics/altIdentifier/doi/10.1103/PhysRevB.94.085139info:eu-repo/semantics/altIdentifier/url/https://arxiv.org/abs/1608.03018info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-03T09:52:59Zoai:ri.conicet.gov.ar:11336/50749instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-03 09:52:59.319CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Qualitative breakdown of the noncrossing approximation for the symmetric one-channel Anderson impurity model at all temperatures
title Qualitative breakdown of the noncrossing approximation for the symmetric one-channel Anderson impurity model at all temperatures
spellingShingle Qualitative breakdown of the noncrossing approximation for the symmetric one-channel Anderson impurity model at all temperatures
Sposetti, Cintia Natalia
KONDO EFFECT
ANDERSON MODEL
NON CROSSING APPROXIMATION
title_short Qualitative breakdown of the noncrossing approximation for the symmetric one-channel Anderson impurity model at all temperatures
title_full Qualitative breakdown of the noncrossing approximation for the symmetric one-channel Anderson impurity model at all temperatures
title_fullStr Qualitative breakdown of the noncrossing approximation for the symmetric one-channel Anderson impurity model at all temperatures
title_full_unstemmed Qualitative breakdown of the noncrossing approximation for the symmetric one-channel Anderson impurity model at all temperatures
title_sort Qualitative breakdown of the noncrossing approximation for the symmetric one-channel Anderson impurity model at all temperatures
dc.creator.none.fl_str_mv Sposetti, Cintia Natalia
Manuel, Luis Oscar
Roura Bas, Pablo Gines
author Sposetti, Cintia Natalia
author_facet Sposetti, Cintia Natalia
Manuel, Luis Oscar
Roura Bas, Pablo Gines
author_role author
author2 Manuel, Luis Oscar
Roura Bas, Pablo Gines
author2_role author
author
dc.subject.none.fl_str_mv KONDO EFFECT
ANDERSON MODEL
NON CROSSING APPROXIMATION
topic KONDO EFFECT
ANDERSON MODEL
NON CROSSING APPROXIMATION
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv The Anderson impurity model is studied by means of the self-consistent hybridization expansions in its noncrossing (NCA) and one-crossing (OCA) approximations. We have found that for the one-channel spin-1/2 particle-hole symmetric Anderson model, the NCA results are qualitatively wrong for any temperature, even when the approximation gives the exact threshold exponents of the ionic states. Actually, the NCA solution describes an overscreened Kondo effect, because it is the same as for the two-channel infinite-U single-level Anderson model. We explicitly show that the NCA is unable to distinguish between these two very different physical systems, independently of temperature. Using the impurity entropy as an example, we show that the low-temperature values of the NCA entropy for the symmetric case yield the limit Simp(T=0)→ln2, which corresponds to the zero temperature entropy of the overscreened Kondo model. Similar pathologies are predicted for any other thermodynamic property. On the other hand, we have found that the OCA approach lifts the artificial mapping between the models and restores correct properties of the ground state, for instance, a vanishing entropy at low enough temperatures Simp(T=0)→0. Our results indicate that the very well known NCA should be used with caution close to the symmetric point of the Anderson model.
Fil: Sposetti, Cintia Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; Argentina
Fil: Manuel, Luis Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; Argentina
Fil: Roura Bas, Pablo Gines. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina
description The Anderson impurity model is studied by means of the self-consistent hybridization expansions in its noncrossing (NCA) and one-crossing (OCA) approximations. We have found that for the one-channel spin-1/2 particle-hole symmetric Anderson model, the NCA results are qualitatively wrong for any temperature, even when the approximation gives the exact threshold exponents of the ionic states. Actually, the NCA solution describes an overscreened Kondo effect, because it is the same as for the two-channel infinite-U single-level Anderson model. We explicitly show that the NCA is unable to distinguish between these two very different physical systems, independently of temperature. Using the impurity entropy as an example, we show that the low-temperature values of the NCA entropy for the symmetric case yield the limit Simp(T=0)→ln2, which corresponds to the zero temperature entropy of the overscreened Kondo model. Similar pathologies are predicted for any other thermodynamic property. On the other hand, we have found that the OCA approach lifts the artificial mapping between the models and restores correct properties of the ground state, for instance, a vanishing entropy at low enough temperatures Simp(T=0)→0. Our results indicate that the very well known NCA should be used with caution close to the symmetric point of the Anderson model.
publishDate 2016
dc.date.none.fl_str_mv 2016-08
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/50749
Sposetti, Cintia Natalia; Manuel, Luis Oscar; Roura Bas, Pablo Gines; Qualitative breakdown of the noncrossing approximation for the symmetric one-channel Anderson impurity model at all temperatures; American Physical Society; Physical Review B: Condensed Matter and Materials Physics; 94; 8; 8-2016; 851391-851398
1098-0121
2469-9969
CONICET Digital
CONICET
url http://hdl.handle.net/11336/50749
identifier_str_mv Sposetti, Cintia Natalia; Manuel, Luis Oscar; Roura Bas, Pablo Gines; Qualitative breakdown of the noncrossing approximation for the symmetric one-channel Anderson impurity model at all temperatures; American Physical Society; Physical Review B: Condensed Matter and Materials Physics; 94; 8; 8-2016; 851391-851398
1098-0121
2469-9969
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/https://journals.aps.org/prb/abstract/10.1103/PhysRevB.94.085139
info:eu-repo/semantics/altIdentifier/doi/10.1103/PhysRevB.94.085139
info:eu-repo/semantics/altIdentifier/url/https://arxiv.org/abs/1608.03018
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
application/pdf
application/pdf
dc.publisher.none.fl_str_mv American Physical Society
publisher.none.fl_str_mv American Physical Society
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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score 13.13397

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