Coincident onset of charge order and pseudogap in a homogeneous high-temperature superconductor.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40234421.
- Also identified by DOI 10.1038/s41467-025-58870-8 and PMC identifier 12000310.
- 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
Understanding high-temperature superconductivity in cuprates requires knowledge of the metallic phase it evolves from, particularly the pseudogap profoundly affecting the electronic properties at low carrier densities. A key question is the influence of chemical disorder, which is ubiquitous but exceedingly difficult to model. Using resonant X-ray scattering, we identified two-dimensional charge order in stoichiometric YBa<sub>2</sub>Cu<sub>4</sub>O<sub>8</sub> (T<sub>c</sub> = 80 K), which is nearly free of chemical disorder. The charge order amplitude shows a concave temperature dependence and vanishes sharply at T* = 200 K, the onset of a prominent pseudogap previously determined by spectroscopy, suggesting a causal link between these phenomena. The gradual onset of charge order in other cuprates is thus likely attributable to an inhomogeneous distribution of charge ordering temperatures due to disorder induced by chemical substitution. The relationship between the pseudogap and the disorder-induced gradual freeze-out of charge carriers remains a central issue in research on high-T<sub>c</sub> superconductors.