NMR studies of coexisting phase of antiferromagnetism and high-Tc superconductivity near Mott transition

2016 Fiscal Year Final Research Report

• Project/Area Number: 26400356
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics II
• Research Institution: Osaka University
• Principal Investigator: Kitaoka Yoshio 大阪大学, 基礎工学研究科, 教授 (70110707)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 銅酸化物高温超伝導 / 高温超伝導発現機構 / NMR/NQR / 反強磁性と超伝導の共存 / 強相関電子系 / 多層系銅酸化物

Outline of Final Research Achievements

High-temperature superconductivity (HTSC) in copper oxides emerges on a layered CuO2 plane when an antiferromagnetic Mott insulator is doped with mobile hole carriers.
We presented our experimental findings　such as the existence of the AFM metallic state in doped Mott insulators, the uniformly mixed phase of AFM and HTSC, and the emergence of d-wave SC with a maximum Tc just outside a critical carrier density, at which the AFM moment on a CuO2 plane disappears. These results can be accounted for by the Mott physics based on the t-J model. The superexchange interaction Jin among spins plays a vital role as a glue for Cooper pairs or mobile spin-singlet pairs, in contrast to the phonon-mediated attractive interaction among electrons established in the Bardeen-Cooper-Schrieffer (BCS) theory.

Free Research Field

強相関電子物理