Unconventional superconductivity and antiferromagnetic quantum critical behavior in the isovalent-doped BaFe2(As1-xPx)2.
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.
Nakai
Y
Y
Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan. nakai@scphys.kyoto-u.ac.jp
Iye
T
T
Kitagawa
S
S
Ishida
K
K
Ikeda
H
H
Kasahara
S
S
Shishido
H
H
Shibauchi
T
T
Matsuda
Y
Y
Terashima
T
T