2026-07-16 東京大学,東京理科大学,上智大学
＜関連情報＞
- https://www.issp.u-tokyo.ac.jp/maincontents/news2.html?pid=31545
- https://www.nature.com/articles/s41467-026-75295-z
多層銅酸化物における外層金属遮蔽による超伝導コヒーレンスの向上 Superconducting coherence boosted by outer-layer metallic screening in multilayered cuprates
Junhyeok Jeong,Kifu Kurokawa,Shiro Sakai,Tomotaka Nakayama,Kotaro Ando,Naoshi Ogane,Soonsang Huh,Matthew D. Watson,Timur K. Kim,Cephise Cacho,Chun Lin,Makoto Hashimoto,Donghui Lu,Takami Tohyama,Kazuyasu Tokiwa & Takeshi Kondo
Nature Communications Published:14 July 2026
DOI:https://doi.org/10.1038/s41467-026-75295-z Unedited version
Abstract
In multilayered high-Tc cuprates, the inner CuO2 planes (IPs) are spatially separated from dopant layers and thus remain cleaner than the outer planes (OPs). Here, we investigate five-layer (Cu,C)Ba2Ca4Cu5Oy (Cu1245) and three-layer Ba2Ca2Cu3O6(F,O)2 (F0223) using angle-resolved photoemission spectroscopy (ARPES) and uncover an unprecedented situation, in which only the IPs become superconducting while the OPs remain metallic at low temperatures. Our model calculations indicate that over 95% of the OP wavefunction remains confined to OP itself, rendering superconducting proximity negligible. This interlayer decoupling realizes an ideal configuration—a single superconducting CuO2 layer screened from the dopant layer-induced disorder by heavily overdoped metallic OPs. The clean CuO2 layer exhibits a large superconducting gap with coherent Bogoliubov peaks extending beyond the antiferromagnetic zone boundary, and a widely extended coherent flat band at the Brillouin zone edge. These findings introduce the “degree of screening” as a physical parameter for probing competition between pseudogap and superconductivity, and for bridging typically disordered real materials with the idealized theoretical models.
