Two distinct superconducting pairing states divided by the nematic end point in FeSe$_{1-x}$S$_{x}$
| Autor: | T. Machida, K. Iwaya, Takasada Shibauchi, Tatsuya Watashige, Yuhki Kohsaka, Shigeru Kasahara, Yasuhiro H. Matsuda, Tetsuo Hanaguri |
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| Rok vydání: | 2017 |
| Předmět: |
Astrophysics::High Energy Astrophysical Phenomena
FOS: Physical sciences 02 engineering and technology 01 natural sciences law.invention Superconductivity (cond-mat.supr-con) Liquid crystal law Lattice (order) Condensed Matter::Superconductivity 0103 physical sciences 010306 general physics Electronic band structure Anisotropy Research Articles Superconductivity Physics Multidisciplinary Condensed matter physics Condensed Matter - Superconductivity Isotropy SciAdv r-articles 021001 nanoscience & nanotechnology Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Condensed Matter::Soft Condensed Matter Applied Sciences and Engineering Pairing Scanning tunneling microscope 0210 nano-technology Research Article |
| Zdroj: | Science Advances |
| DOI: | 10.48550/arxiv.1710.02276 |
| Popis: | Unconventional superconductivity often competes or coexists with other electronic orders. In iron-based superconductors, relationship between superconductivity and the nematic state, where the lattice rotational symmetry is spontaneously broken in the electronic states, has been discussed but unclear. Using spectroscopic-imaging scanning tunneling microscopy, we investigate how the band structure and the superconducting gap evolve in FeSe$_{1-x}$S$_x$, as the sulfur substitution suppresses nematicity that eventually diminishes at the nematic end point (NEP) at $x=0.17$. Anisotropic quasiparticle-interference patterns, which represent the nematic band structure, gradually become isotropic with increasing $x$ without detectable anomalies in the band parameters at the NEP. By contrast, the superconducting gap, which is almost intact in the nematic phase, suddenly shrinks as soon as $x$ exceeds the NEP. Our observation implies that the presence or absence of nematicity results in two distinct pairing states, whereas the pairing interaction is insensitive to the strength of nematicity. This provides a clue for understanding the pairing mechanism. Comment: 9 pages, 4 figures. Supplementary information is available at http://www.riken.jp/epmrt/Hanaguri/SI/FeSeS_QPI_SI.pdf |
| Databáze: | OpenAIRE |
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