title: Unconventional superconductivity and antiferromagnetic quantum critical behavior in the isovalent-doped BaFe2(As1-xPx)2.
abstract: Spin dynamics evolution of BaFe2(As(1-x)Px){2} was probed as a function of P concentration via 31P NMR. Our NMR study reveals that two-dimensional antiferromagnetic (AF) fluctuations are notably enhanced with little change in static susceptibility on approaching the AF phase from the superconducting dome. Moreover, the magnetically ordered temperature θ deduced from the relaxation rate vanishes at optimal doping. These results provide clear-cut evidence for a quantum-critical point, suggesting that the AF fluctuations associated with the quantum-critical point play a central role in the high-T(c) superconductivity.
authors.affiliation: Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan. nakai@scphys.kyoto-u.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Nakai
authors.forename: T
authors.initials: T
authors.lastname: Iye
authors.forename: S
authors.initials: S
authors.lastname: Kitagawa
authors.forename: K
authors.initials: K
authors.lastname: Ishida
authors.forename: H
authors.initials: H
authors.lastname: Ikeda
authors.forename: S
authors.initials: S
authors.lastname: Kasahara
authors.forename: H
authors.initials: H
authors.lastname: Shishido
authors.forename: T
authors.initials: T
authors.lastname: Shibauchi
authors.forename: Y
authors.initials: Y
authors.lastname: Matsuda
authors.forename: T
authors.initials: T
authors.lastname: Terashima