Metallic islands in the Kondo insulator SmB6
Autor(a) principal: | |
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Data de Publicação: | 2020 |
Outros Autores: | , , , , , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1103/PhysRevResearch.2.043181 http://hdl.handle.net/11449/209860 |
Resumo: | The predicted interplay between Kondo physics and nontrivial topology in SmB6 has stimulated many experimental reports, some of which are in apparent contradiction. The origin of the dispute may lie in the fragility of the Kondo insulating phase in the presence of Sm vacancies (Kondo holes) and/or natural impurities, such as Gd3+. In this work, we locally investigate this fragility for Al flux grown Sm1-xGdxB6 single crystals (0 <= x <= 0.02) by combining electron spin resonance (ESR) and complementary bulk measurements. The Gd3+ ESR spectra in a highly dilute regime (x similar to 0.0004) display the features of an insulating cubic environment. Remarkably, a metallic ESR line shape is observed for more concentrated samples (x similar to 0.004), even though these systems are still in a reasonably dilute regime and show insulating dc electrical resistivity. Our data indicate that the Kondo insulating state is destroyed locally around impurities before a global percolation occurs. This result not only explains the discrepancy between dc and ac conductivity but also provides a scenario to explain the presence of quantum oscillations in magnetization in the absence of quantum oscillations in electrical resistivity. |
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Metallic islands in the Kondo insulator SmB6The predicted interplay between Kondo physics and nontrivial topology in SmB6 has stimulated many experimental reports, some of which are in apparent contradiction. The origin of the dispute may lie in the fragility of the Kondo insulating phase in the presence of Sm vacancies (Kondo holes) and/or natural impurities, such as Gd3+. In this work, we locally investigate this fragility for Al flux grown Sm1-xGdxB6 single crystals (0 <= x <= 0.02) by combining electron spin resonance (ESR) and complementary bulk measurements. The Gd3+ ESR spectra in a highly dilute regime (x similar to 0.0004) display the features of an insulating cubic environment. Remarkably, a metallic ESR line shape is observed for more concentrated samples (x similar to 0.004), even though these systems are still in a reasonably dilute regime and show insulating dc electrical resistivity. Our data indicate that the Kondo insulating state is destroyed locally around impurities before a global percolation occurs. This result not only explains the discrepancy between dc and ac conductivity but also provides a scenario to explain the presence of quantum oscillations in magnetization in the absence of quantum oscillations in electrical resistivity.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FINEP-BrazilNSFU.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Science and EngineeringUniv Estadual Campinas, Inst Fis Gleb Wataghin, BR-13083859 Campinas, SP, BrazilMax Planck Inst Chem Phys Solids, D-01187 Dresden, GermanyLos Alamos Natl Lab, Los Alamos, NM 87545 USAUNESP, Fac Ciencias, POSMAT, CP 473, BR-17033360 Bauru, SP, BrazilUNESP, Fac Ciencias, Dept Fis, CP 473, BR-17033360 Bauru, SP, BrazilUniv Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USAUNESP, Fac Ciencias, POSMAT, CP 473, BR-17033360 Bauru, SP, BrazilUNESP, Fac Ciencias, Dept Fis, CP 473, BR-17033360 Bauru, SP, BrazilFAPESP: 2018/11364-7FAPESP: 2017/10581-1FAPESP: 2016/14436-3FAPESP: 2013/17427-7FAPESP: 2012/04870-7FAPESP: 2012/05903-6CNPq: 309483/2018-2CNPq: 442230/2014-1CNPq: 304649/2013-9CNPq: 141026/2017-0NSF: 1708199Amer Physical SocUniversidade Estadual de Campinas (UNICAMP)Max Planck Inst Chem Phys SolidsLos Alamos Natl LabUniversidade Estadual Paulista (Unesp)Univ Calif IrvineSouza, J. C.Rosa, P. F. S.Sichelschmidt, J.Carlone, M. [UNESP]Venegas, P. A. [UNESP]Malcolms, M. O.Menegasso, P. M.Urbano, R. R.Fisk, Z.Pagliuso, P. G.2021-06-25T12:31:44Z2021-06-25T12:31:44Z2020-11-03info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article8http://dx.doi.org/10.1103/PhysRevResearch.2.043181Physical Review Research. College Pk: Amer Physical Soc, v. 2, n. 4, 8 p., 2020.http://hdl.handle.net/11449/20986010.1103/PhysRevResearch.2.043181WOS:000605405100009Web of Sciencereponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengPhysical Review Researchinfo:eu-repo/semantics/openAccess2024-04-25T17:40:31Zoai:repositorio.unesp.br:11449/209860Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-04-25T17:40:31Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Metallic islands in the Kondo insulator SmB6 |
title |
Metallic islands in the Kondo insulator SmB6 |
spellingShingle |
Metallic islands in the Kondo insulator SmB6 Souza, J. C. |
title_short |
Metallic islands in the Kondo insulator SmB6 |
title_full |
Metallic islands in the Kondo insulator SmB6 |
title_fullStr |
Metallic islands in the Kondo insulator SmB6 |
title_full_unstemmed |
Metallic islands in the Kondo insulator SmB6 |
title_sort |
Metallic islands in the Kondo insulator SmB6 |
author |
Souza, J. C. |
author_facet |
Souza, J. C. Rosa, P. F. S. Sichelschmidt, J. Carlone, M. [UNESP] Venegas, P. A. [UNESP] Malcolms, M. O. Menegasso, P. M. Urbano, R. R. Fisk, Z. Pagliuso, P. G. |
author_role |
author |
author2 |
Rosa, P. F. S. Sichelschmidt, J. Carlone, M. [UNESP] Venegas, P. A. [UNESP] Malcolms, M. O. Menegasso, P. M. Urbano, R. R. Fisk, Z. Pagliuso, P. G. |
author2_role |
author author author author author author author author author |
dc.contributor.none.fl_str_mv |
Universidade Estadual de Campinas (UNICAMP) Max Planck Inst Chem Phys Solids Los Alamos Natl Lab Universidade Estadual Paulista (Unesp) Univ Calif Irvine |
dc.contributor.author.fl_str_mv |
Souza, J. C. Rosa, P. F. S. Sichelschmidt, J. Carlone, M. [UNESP] Venegas, P. A. [UNESP] Malcolms, M. O. Menegasso, P. M. Urbano, R. R. Fisk, Z. Pagliuso, P. G. |
description |
The predicted interplay between Kondo physics and nontrivial topology in SmB6 has stimulated many experimental reports, some of which are in apparent contradiction. The origin of the dispute may lie in the fragility of the Kondo insulating phase in the presence of Sm vacancies (Kondo holes) and/or natural impurities, such as Gd3+. In this work, we locally investigate this fragility for Al flux grown Sm1-xGdxB6 single crystals (0 <= x <= 0.02) by combining electron spin resonance (ESR) and complementary bulk measurements. The Gd3+ ESR spectra in a highly dilute regime (x similar to 0.0004) display the features of an insulating cubic environment. Remarkably, a metallic ESR line shape is observed for more concentrated samples (x similar to 0.004), even though these systems are still in a reasonably dilute regime and show insulating dc electrical resistivity. Our data indicate that the Kondo insulating state is destroyed locally around impurities before a global percolation occurs. This result not only explains the discrepancy between dc and ac conductivity but also provides a scenario to explain the presence of quantum oscillations in magnetization in the absence of quantum oscillations in electrical resistivity. |
publishDate |
2020 |
dc.date.none.fl_str_mv |
2020-11-03 2021-06-25T12:31:44Z 2021-06-25T12:31:44Z |
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://dx.doi.org/10.1103/PhysRevResearch.2.043181 Physical Review Research. College Pk: Amer Physical Soc, v. 2, n. 4, 8 p., 2020. http://hdl.handle.net/11449/209860 10.1103/PhysRevResearch.2.043181 WOS:000605405100009 |
url |
http://dx.doi.org/10.1103/PhysRevResearch.2.043181 http://hdl.handle.net/11449/209860 |
identifier_str_mv |
Physical Review Research. College Pk: Amer Physical Soc, v. 2, n. 4, 8 p., 2020. 10.1103/PhysRevResearch.2.043181 WOS:000605405100009 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Physical Review Research |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
8 |
dc.publisher.none.fl_str_mv |
Amer Physical Soc |
publisher.none.fl_str_mv |
Amer Physical Soc |
dc.source.none.fl_str_mv |
Web of Science reponame:Repositório Institucional da UNESP instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Repositório Institucional da UNESP |
collection |
Repositório Institucional da UNESP |
repository.name.fl_str_mv |
Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
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1799965749913059328 |