Superconducting gap and critical behavior in the Iron-Pnictides
In the phase diagram of iron pnictides, superconductivity arises at the border of antiferromagnetism, which raises the question of the role of symmetry of the gap and quantum criticality. Although more than 15-years of extensive research, the microscopic origin of the pairing symmetry inside the sup...
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| Format: | Article |
| Language: | English |
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Elsevier
2023-09-01
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| Series: | Results in Physics |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2211379723006253 |
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| author | M.M.E. Barakat T.A. Abdel-Baset M. Belhaj D. El-Said Bakeer A.N. Vasiliev M. Abdel-Hafiez |
| author_facet | M.M.E. Barakat T.A. Abdel-Baset M. Belhaj D. El-Said Bakeer A.N. Vasiliev M. Abdel-Hafiez |
| author_sort | M.M.E. Barakat |
| collection | DOAJ |
| description | In the phase diagram of iron pnictides, superconductivity arises at the border of antiferromagnetism, which raises the question of the role of symmetry of the gap and quantum criticality. Although more than 15-years of extensive research, the microscopic origin of the pairing symmetry inside the superconducting (SC) dome and its link to quantum criticality still remains elusive. Here, we report two new findings on BaFe2−xNixAs2: (1) A sharp peak in the x-dependence of the lower and upper critical fields, the SC critical current density Jc, the size of the jump in the specific heat ΔCel/T and the Sommerfeld coefficient (γ) at the optimum composition x = 0.10, where the SC transition temperature Tc reaches a maximum. Our obtained reliable values as a function of doping of the normal-state Sommerfeld coefficient increase with doping, illustrating the strong competition between magnetism and superconductivity and attributed to closing of spin density wave gap with Ni doping. (2) We show that doping induced a sudden change of the gap structure from nodeless to nodal. Our results imply that the superconductivity in BaFe2−xNixAs2 is closely linked to the quantum criticality and is characterized by a complex order parameter. |
| first_indexed | 2024-03-12T00:05:47Z |
| format | Article |
| id | doaj.art-00581a28379d4fc9975137ab5c2069a6 |
| institution | Directory Open Access Journal |
| issn | 2211-3797 |
| language | English |
| last_indexed | 2024-03-12T00:05:47Z |
| publishDate | 2023-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Results in Physics |
| spelling | doaj.art-00581a28379d4fc9975137ab5c2069a62023-09-17T04:56:24ZengElsevierResults in Physics2211-37972023-09-0152106832Superconducting gap and critical behavior in the Iron-PnictidesM.M.E. Barakat0T.A. Abdel-Baset1M. Belhaj2D. El-Said Bakeer3A.N. Vasiliev4M. Abdel-Hafiez5Department of Physics, Faculty of Science, Taibah University, Yanbu, Saudi Arabia; Department of Physics, Faculty of Science, Alexandria University, Alexandria, EgyptDepartment of Physics, Faculty of Science, Taibah University, Yanbu, Saudi Arabia; Department of Physics, Faculty of Science, Fayoum University, Fayoum, EgyptDepartment of Physics, Faculty of Science, Taibah University, Yanbu, Saudi ArabiaDepartment of Physics, Faculty of Science and Arts, Taibah University, Al-Ula, Saudi Arabia; Department of Physics, Faculty of Science, Damanhour University, Damnhour, EgyptLomonosov Moscow State University, Moscow 119991, Russia; National University of Science and Technology “MISiS”, Moscow 119049, RussiaDepartment of Physics and Astronomy, Uppsala University, Box 516, Uppsala SE-75120, Sweden; Department of Applied Physics and Astronomy, University of Sharjah, P. O. Box 27272, Sharjah, United Arab Emirates; Corresponding author.In the phase diagram of iron pnictides, superconductivity arises at the border of antiferromagnetism, which raises the question of the role of symmetry of the gap and quantum criticality. Although more than 15-years of extensive research, the microscopic origin of the pairing symmetry inside the superconducting (SC) dome and its link to quantum criticality still remains elusive. Here, we report two new findings on BaFe2−xNixAs2: (1) A sharp peak in the x-dependence of the lower and upper critical fields, the SC critical current density Jc, the size of the jump in the specific heat ΔCel/T and the Sommerfeld coefficient (γ) at the optimum composition x = 0.10, where the SC transition temperature Tc reaches a maximum. Our obtained reliable values as a function of doping of the normal-state Sommerfeld coefficient increase with doping, illustrating the strong competition between magnetism and superconductivity and attributed to closing of spin density wave gap with Ni doping. (2) We show that doping induced a sudden change of the gap structure from nodeless to nodal. Our results imply that the superconductivity in BaFe2−xNixAs2 is closely linked to the quantum criticality and is characterized by a complex order parameter.http://www.sciencedirect.com/science/article/pii/S2211379723006253ElectricMagneticDoping effectCritical behaviorTemperature coefficient of resistance |
| spellingShingle | M.M.E. Barakat T.A. Abdel-Baset M. Belhaj D. El-Said Bakeer A.N. Vasiliev M. Abdel-Hafiez Superconducting gap and critical behavior in the Iron-Pnictides Results in Physics Electric Magnetic Doping effect Critical behavior Temperature coefficient of resistance |
| title | Superconducting gap and critical behavior in the Iron-Pnictides |
| title_full | Superconducting gap and critical behavior in the Iron-Pnictides |
| title_fullStr | Superconducting gap and critical behavior in the Iron-Pnictides |
| title_full_unstemmed | Superconducting gap and critical behavior in the Iron-Pnictides |
| title_short | Superconducting gap and critical behavior in the Iron-Pnictides |
| title_sort | superconducting gap and critical behavior in the iron pnictides |
| topic | Electric Magnetic Doping effect Critical behavior Temperature coefficient of resistance |
| url | http://www.sciencedirect.com/science/article/pii/S2211379723006253 |
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