P-31 and As-75 NMR evidence for a residual density of states at zero energy in superconducting BaFe2(As0.67P0.33)(2)

P-31 and As-75 NMR measurements were performed in superconducting BaFe2(As0.67P0.33)(2) with T-c = 30 K. The nuclear-spin-lattice relaxation rate T-1(-1) and the Knight shift in the normal state indicate the development of antiferromagnetic fluctuations, and T-1(-1) in the superconducting (SC) state decreases without a coherence peak just below T-c, as observed in (Ba1-xKx)Fe2As2. In contrast to other iron arsenide superconductors, the T-1(-1) proportional to T behavior is observed below 4 K, indicating the presence of a residual density of states at zero energy. Our results suggest that strikingly different SC gaps appear in BaFe2(As1-xPx)(2) despite a comparable T-c value, an analogous phase diagram, and similar Fermi surfaces to (Ba1-xKx)Fe2As2.