NMR/NQRによる強相関電子系の研究

微視的な実験手段から

抄録

We report on an intimate interplay between superconductivity (SC) and antiferromagnetism (AFM) in CeRhIn₅ under pressure and multilayered high-T_c cuprates via the NMR/NQR measurements. The experiments on CeRhIn₅ has revealed that a first-order quantum phase transition (QPT) occurs around P_c-2 GPa from the AFM to the paramagnetism in the superconducting regime and the novel superconducting nature in the coexistent phase of AFM and SC. The site selective Cu-NMR study demonstrated that the under-doped five-layered high-T_c cuprate, HgBa₂Ca₄Cu₅O_12+δ with T_c=72 K can uniformly coexist on the microscopic level with the AFM. This is the first microscopic evidence for the uniform mixed phase of AFM and SC on a single CuO₂ plane in a simple environment without any vortex lattice and/or stripe order.