Gap symmetry of the heavy fermion superconductor CeCu$_2$Si$_2$ at ambient pressure
| Autor: | Li, Yu, Liu, Min, Fu, Zhaoming, Chen, Xiangrong, Yang, Fan, Yang, Yi-feng |
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| Rok vydání: | 2018 |
| Předmět: | |
| Zdroj: | Phys. Rev. Lett. 120, 217001 (2018) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevLett.120.217001 |
| Popis: | Recent observations of two nodeless gaps in superconducting CeCu$_2$Si$_2$ have raised intensive debates on its exact gap symmetry, while a satisfactory theoretical basis is still lacking. Here we propose a phenomenological approach to calculate the superconducting gap functions, taking into consideration both the realistic Fermi surface topology and the intra- and interband quantum critical scatterings. Our calculations yield a nodeless $s^\pm$-wave solution in the presence of strong interband pairing interaction, in good agreement with experiments. This provides a possible basis for understanding the superconducting gap symmetry of CeCu$_2$Si$_2$ at ambient pressure and indicates the potential importance of multiple Fermi surfaces and interband pairing interaction in understanding heavy fermion superconductivity. Comment: 7 pages, 5 figures |
| Databáze: | arXiv |
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