Spin excitations in hole-overdoped iron-based superconductors
| Autor: | Horigane, K., Kihou, K., Fujita, K., Kajimoto, R., Ikeuchi, K., Ji, S., Akimitsu, J., Lee, C. H. |
|---|---|
| Rok vydání: | 2016 |
| Předmět: | |
| Zdroj: | Sci. Rep. 6, 33303 (2016) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1038/srep33303 |
| Popis: | Understanding the overall features of magnetic excitation is essential for clarifying the mechanism of Cooper pair formation in iron-based superconductors. In particular, clarifying the relationship between magnetism and superconductivity is a central challenge because magnetism may play a key role in their exotic superconductivity. BaFe2As2 is one of ideal systems for such investigation because its superconductivity can be induced in several ways, allowing a comparative examination. Here we report a study on the spin fluctuations of the hole-overdoped iron-based superconductors Ba1-xKxFe2As2 (x = 0.5 and 1.0; Tc = 36 K and 3.4 K, respectively) over the entire Brillouin zone using inelastic neutron scattering. We find that their spin spectra consist of spin wave and chimney-like dispersions. The chimney-like dispersion can be attributed to the itinerant character of magnetism. The band width of the spin wave-like dispersion is almost constant from the non-doped to optimum-doped region, which is followed by a large reduction in the overdoped region. This suggests that the superconductivity is suppressed by the reduction of magnetic exchange couplings, indicating a strong relationship between magnetism and superconductivity in iron-based superconductors. Comment: 16 pages, 4 figures |
| Databáze: | arXiv |
| Externí odkaz: |
|