Momentum-dependent sign inversion of orbital order in superconducting FeSe
| Autor: | Takahiro Shimojima, Hiroshi Kontani, Youichi Yamakawa, M. Sakano, T. Sonobe, A. Nakamura, Makoto Kuwata-Gonokami, Ryo Kobayashi, J. Omachi, Yuji Matsuda, Shigeru Kasahara, Kosuke Yoshioka, Takasada Shibauchi, Tatsuya Watashige, H. Tsuji, Yasuhiro Suzuki, Kyoko Ishizaka |
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| Rok vydání: | 2015 |
| Předmět: |
Physics
Superconductivity Atomic orbital Condensed matter physics Photoemission spectroscopy Condensed Matter::Superconductivity Structural transition Orthorhombic crystal system Electronic structure Condensed Matter Physics Polarization (waves) Electronic Optical and Magnetic Materials Fermi Gamma-ray Space Telescope |
| Zdroj: | Physical Review B. 92 |
| ISSN: | 1550-235X 1098-0121 |
| DOI: | 10.1103/physrevb.92.205117 |
| Popis: | We investigate the electronic reconstruction across the tetragonal-orthorhombic structural transition in FeSe by employing polarization-dependent angle-resolved photoemission spectroscopy on detwinned single crystals. Across the structural transition, the electronic structures around the $\mathrm{\ensuremath{\Gamma}}$ and $M$ points are modified from fourfold to twofold symmetry due to the lifting of degeneracy in ${d}_{xz}/{d}_{yz}$ orbitals. The ${d}_{xz}$ band shifts upward at the $\mathrm{\ensuremath{\Gamma}}$ point, while it moves downward at the $M$ point, suggesting that the electronic structure of orthorhombic FeSe is characterized by a momentum-dependent sign-changing orbital polarization. Due to this sign-changing orbital order, the elongated directions of the elliptical Fermi surfaces at the $\mathrm{\ensuremath{\Gamma}}$ and $M$ points are rotated by 90\ifmmode^\circ\else\textdegree\fi{} with respect to each other, which makes the nesting condition between these FSs imperfect. The present result, supported by calculations, indicates the possible suppression of the spin-fluctuation mediated superconductivity in the orthorhombic FeSe, as compared to the orbital-ordered state without sign change. |
| Databáze: | OpenAIRE |
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