[12p-N401-1~8] 11.1 Fundamental properties

[12p-N401-8] Superconductivity in Pr₂Ba₄Cu₇O_15-δ II:
Cu Nuclear-Spin Evidence of No Contribution of CuO₂ Planes to Superconductivity

Sotaro Nishioka¹, Shunsaku Nakagawa¹, Mitsuharu Yashima¹, Hidekazu Mukuda¹, Mamoru Yogi², Kosuke Ikeda³, Dwi Prananto³, 〇Susumu Sasaki³, Jun-ichi Shimoyama⁴ (1.Osaka Univ., 2.Ryukyu Univ., 3.Niigata Univ., 4.Aoyama-Gakuin Univ.)

Keywords:cuprate superconductor, nuclear spin, chain-driven superconductivity

Unlike other cuprate superconductors, it is strongly suggested that the CuO₂ planes do not contribute to the superconductivity in Pr₂Ba₄Cu₇O₁₅, Pr247. In the previous conference, we mentioned that, from Cu nuclear-spin measurements on well-characterized Pr247, all the Cu sites in the planes are in an antiferromagnetically ordered state well below T_c. Here, based on a detailed analysis on well-refined Cu nuclear-spin spectrum, we have clarified that the CuO₂ planes are not metallic but insulating. This indicates that the superconductivity of Pr247 is not driven by the CuO₂ planes.