Superconductivity emerging from the Né el state in infinite-stage single-layer cuprate La₂CuO_4+δ

IHARA Yoshihiko

Department of Physics

Aug. 28, 2025

わずかに酸素をドープした単層型銅酸化物La2CuO4+δで、ネール状態と超伝導状態の共存状態が見つかった。CuO₂層上で広がりを持つ伝導キャリア（青丸）が作る超伝導状態と、Cuに局在する磁気モーメント（赤矢印）が作るネール状態は、本来は水と油のように相容れない状態である。対立する性質が融和した斬新な共存状態が、最古の銅酸化物で実現していたことが分かった。

Press release (in Japanese)

Abstract
In copper oxides (cuprates) with single CuO₂ layer such as La₂−xBa(Sr)_xCuO₄, antiferromagnetism coexists with superconductivity at small doping levels x, where chemical disorders are significant. Here, we report that superconductivity occurs in a uniform and fully ordered Néel state in a single-layer cuprate La₂CuO_4+δ with a small amount of excess oxygen (δ = 0.015) as demonstrated by the ¹³⁹La nuclear quadrupole resonance measurement. A uniform oxygen distribution in the crystal is crucial for……

Read the original article on Scientific Reports

Article inforamation
Yoshihiko Ihara, Ramender Kumar, Kota Miyakoshi , Migaku Oda, and Kenji Ishida, Superconductivity emerging from the Néel state in infinite-stage single-layer cuprate La₂CuO_4+δ, Sci Rep 15, 27640 (2025)
DOI: 10.1038/s41598-025-11950-7