Abstract
Elucidating spin correlations in the parent compounds of high-temperature superconductors is crucial for understanding superconductivity. We used neutron scattering to study spin correlations in Li1-xFexODFeSe, an insulating material with reduced electron carriers compared to its superconducting counterpart (Tc=41 K), serving as the undoped parent compound. Our findings show a reduced total fluctuating moment in this insulator relative to FeSe and 122 iron pnictides, likely due to increased interlayer distances from intercalation, which enhance fluctuations and reduce the intensity of spin excitations. Moreover, we observed a V-shaped spin wavelike excitation dispersion, contrasting with the twisted hourglass pattern in the superconducting counterpart. Electron doping shifts spin excitation from (π,0) point to an incommensurate position towards (π,π) direction below 65 meV. This transition from V-shaped to hourglasslike dispersion, akin to behaviors in hole-doped cuprates, suggests a potential shared mechanism in magnetism and superconductivity across these diverse systems.
| Original language | English |
|---|---|
| Article number | 016501 |
| Journal | Physical Review Letters |
| Volume | 134 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 10 2025 |
Funding
This work was supported by National Key R&D Program of China (2022YFA1403202), the Key Program of National Natural Science Foundation of China (Grant No. 12234006), the Shanghai Municipal Science and Technology Major Project (Grant No. 2019SHZDZX01), the Innovation Program for Quantum Science and Technology (Grant No. 2024ZD0300103), and the Large Scientific Facility Open Subject of Songshan Lake Laboratory (Grant No. DG23313511). H. W. was supported by the Youth Foundation of the National Natural Science Foundation of China (Grant No. 12204108). B. P. is supported by the Natural Science Foundation of Shandong Province (Grant No. ZR2020YQ03). Y. F. is supported by the National Key R&D Program of China (Grant No. 2022YFA1604104) and the Fundamental and Applied Fundamental Research Grant of Guangdong Province (Grant No. 2021B1515120015). A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory.