Charge order driven by multiple-Q spin fluctuations in heavily electron-doped iron selenide superconductors.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37041177.
- Also identified by DOI 10.1038/s41467-023-37792-3 and PMC identifier 10090174.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Intertwined spin and charge orders have been widely studied in high-temperature superconductors, since their fluctuations may facilitate electron pairing; however, they are rarely identified in heavily electron-doped iron selenides. Here, using scanning tunneling microscopy, we show that when the superconductivity of (Li<sub>0.84</sub>Fe<sub>0.16</sub>OH)Fe<sub>1-x</sub>Se is suppressed by introducing Fe-site defects, a short-ranged checkerboard charge order emerges, propagating along the Fe-Fe directions with an approximately 2a<sub>Fe</sub> period. It persists throughout the whole phase space tuned by Fe-site defect density, from a defect-pinned local pattern in optimally doped samples to an extended order in samples with lower T<sub>c</sub> or non-superconducting. Intriguingly, our simulations indicate that the charge order is likely driven by multiple-Q spin density waves originating from the spin fluctuations observed by inelastic neutron scattering. Our study proves the presence of a competing order in heavily electron-doped iron selenides, and demonstrates the potential of charge order as a tool to detect spin fluctuations.