High-temperature superconductivity from fine-tuning of Fermi-surface singularities in iron oxypnictides
In the family of the iron-based superconductors, the REFeAsO-type compounds (with RE being a rare-earth metal) exhibit the highest bulk superconducting transition temperatures (Tc) up to 55 K and thus hold the key to the elusive pairing mechanism. Recently, it has been demonstrated that the intrinsi...
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Nature Publishing Group
2015
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| Online Access: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4683369/ |
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pubmed-46833692015-12-21 High-temperature superconductivity from fine-tuning of Fermi-surface singularities in iron oxypnictides Charnukha, A. Evtushinsky, D. V. Matt, C. E. Xu, N. Shi, M. Büchner, B. Zhigadlo, N. D. Batlogg, B. Borisenko, S. V. Article In the family of the iron-based superconductors, the REFeAsO-type compounds (with RE being a rare-earth metal) exhibit the highest bulk superconducting transition temperatures (Tc) up to 55 K and thus hold the key to the elusive pairing mechanism. Recently, it has been demonstrated that the intrinsic electronic structure of SmFe0.92Co0.08AsO (Tc = 18 K) is highly nontrivial and consists of multiple band-edge singularities in close proximity to the Fermi level. However, it remains unclear whether these singularities are generic to the REFeAsO-type materials and if so, whether their exact topology is responsible for the aforementioned record Tc. In this work, we use angle-resolved photoemission spectroscopy (ARPES) to investigate the inherent electronic structure of the NdFeAsO0.6F0.4 compound with a twice higher Tc = 38 K. We find a similarly singular Fermi surface and further demonstrate that the dramatic enhancement of superconductivity in this compound correlates closely with the fine-tuning of one of the band-edge singularities to within a fraction of the superconducting energy gap Δ below the Fermi level. Our results provide compelling evidence that the band-structure singularities near the Fermi level in the iron-based superconductors must be explicitly accounted for in any attempt to understand the mechanism of superconducting pairing in these materials. Nature Publishing Group 2015-12-18 /pmc/articles/PMC4683369/ /pubmed/26678565 http://dx.doi.org/10.1038/srep18273 Text en Copyright © 2015, Macmillan Publishers Limited http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
| repository_type |
Open Access Journal |
| institution_category |
Foreign Institution |
| institution |
US National Center for Biotechnology Information |
| building |
NCBI PubMed |
| collection |
Online Access |
| language |
English |
| format |
Online |
| author |
Charnukha, A. Evtushinsky, D. V. Matt, C. E. Xu, N. Shi, M. Büchner, B. Zhigadlo, N. D. Batlogg, B. Borisenko, S. V. |
| spellingShingle |
Charnukha, A. Evtushinsky, D. V. Matt, C. E. Xu, N. Shi, M. Büchner, B. Zhigadlo, N. D. Batlogg, B. Borisenko, S. V. High-temperature superconductivity from fine-tuning of Fermi-surface singularities in iron oxypnictides |
| author_facet |
Charnukha, A. Evtushinsky, D. V. Matt, C. E. Xu, N. Shi, M. Büchner, B. Zhigadlo, N. D. Batlogg, B. Borisenko, S. V. |
| author_sort |
Charnukha, A. |
| title |
High-temperature superconductivity from fine-tuning of Fermi-surface singularities in iron oxypnictides |
| title_short |
High-temperature superconductivity from fine-tuning of Fermi-surface singularities in iron oxypnictides |
| title_full |
High-temperature superconductivity from fine-tuning of Fermi-surface singularities in iron oxypnictides |
| title_fullStr |
High-temperature superconductivity from fine-tuning of Fermi-surface singularities in iron oxypnictides |
| title_full_unstemmed |
High-temperature superconductivity from fine-tuning of Fermi-surface singularities in iron oxypnictides |
| title_sort |
high-temperature superconductivity from fine-tuning of fermi-surface singularities in iron oxypnictides |
| description |
In the family of the iron-based superconductors, the REFeAsO-type compounds (with RE being a rare-earth metal) exhibit the highest bulk superconducting transition temperatures (Tc) up to 55 K and thus hold the key to the elusive pairing mechanism. Recently, it has been demonstrated that the intrinsic electronic structure of SmFe0.92Co0.08AsO (Tc = 18 K) is highly nontrivial and consists of multiple band-edge singularities in close proximity to the Fermi level. However, it remains unclear whether these singularities are generic to the REFeAsO-type materials and if so, whether their exact topology is responsible for the aforementioned record Tc. In this work, we use angle-resolved photoemission spectroscopy (ARPES) to investigate the inherent electronic structure of the NdFeAsO0.6F0.4 compound with a twice higher Tc = 38 K. We find a similarly singular Fermi surface and further demonstrate that the dramatic enhancement of superconductivity in this compound correlates closely with the fine-tuning of one of the band-edge singularities to within a fraction of the superconducting energy gap Δ below the Fermi level. Our results provide compelling evidence that the band-structure singularities near the Fermi level in the iron-based superconductors must be explicitly accounted for in any attempt to understand the mechanism of superconducting pairing in these materials. |
| publisher |
Nature Publishing Group |
| publishDate |
2015 |
| url |
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4683369/ |
| _version_ |
1613514118600327168 |