Direct evidence of uneven dxz and dyz orbital occupation in the superconducting state of iron pnictide
| Autor: | Zbigniew Bukowski, Marcin Matusiak, Michał Jurczyszyn, D. Rybicki, Marcin Sikora, Czesław Kapusta, Michal Babij, Joanna Stępień, Kamil Goc, Tomasz Strączek, Łukasz Gondek, M. Zając |
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| Rok vydání: | 2020 |
| Předmět: |
Physics
Superconductivity Condensed matter physics Direct evidence 02 engineering and technology 021001 nanoscience & nanotechnology Polarization (waves) Linear dichroism 01 natural sciences Tetragonal crystal system Atomic orbital Condensed Matter::Superconductivity 0103 physical sciences 010306 general physics 0210 nano-technology Pnictogen |
| Zdroj: | Physical Review B. 102 |
| ISSN: | 2469-9969 2469-9950 |
| DOI: | 10.1103/physrevb.102.195126 |
| Popis: | The origin of nematicity and its relation to superconductivity in iron pnictide high-temperature superconductors remains unclear. One of its possible sources is the uneven occupation of Fe ${d}_{xz}$ and ${d}_{yz}$ orbitals. Here, by using x-ray linear dichroism technique, we show that such an imbalance is present in $\mathrm{Eu}{({\mathrm{Fe}}_{1\ensuremath{-}x}{\mathrm{Co}}_{x})}_{2}{\mathrm{As}}_{2}$ single crystals deep in the tetragonal phase and also in the superconducting state, where we find that the ${d}_{xz}$ orbital has a higher occupation as indicated by an x-ray linear dichroism magnitude of 1.5%. Our result shows the importance of orbital polarization in the theoretical description of nematicity and superconductivity, particularly for determination of the superconducting gap symmetry, which is affected by orbital fluctuations. |
| Databáze: | OpenAIRE |
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