High temperature superconductivity at FeSe/LaFeO<sub>3</sub> interface.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 34635672.
- Also identified by DOI 10.1038/s41467-021-26201-2 and PMC identifier 8505662.
- 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
Enormous enhancement of superconducting pairing temperature (T<sub>g</sub>) to 65 K in FeSe/SrTiO<sub>3</sub> has made it a spotlight. Despite the effort of interfacial engineering, FeSe interfaced with TiO<sub>x</sub> remains the unique case in hosting high T<sub>g</sub>, hindering a decisive understanding on the general mechanism and ways to further improving T<sub>g</sub>. Here we constructed a new high-T<sub>g</sub> interface, single-layer FeSe interfaced with FeO<sub>x</sub>-terminated LaFeO<sub>3</sub>. Large superconducting gap and diamagnetic response evidence that the superconducting pairing can emerge near 80 K, highest amongst all-known interfacial superconductors. Combining various techniques, we reveal interfacial charge transfer and strong interfacial electron-phonon coupling (EPC) in FeSe/LaFeO<sub>3</sub>, showing that the cooperative pairing mechanism works beyond FeSe-TiO<sub>x</sub>. Intriguingly, the stronger interfacial EPC than that in FeSe/SrTiO<sub>3</sub> is likely induced by the stronger interfacial bonding in FeSe/LaFeO<sub>3</sub>, and can explain the higher T<sub>g</sub> according to recent theoretical calculations, pointing out a workable route in designing new interfaces to achieve higher T<sub>g</sub>.