TY - JOUR
T1 - Incommensurate spin-density wave and a multiband superconducting phase in NaxFeAs revealed by nuclear magnetic resonance
AU - Klanjšek, M.
AU - Jeglič, P.
AU - Lv, B.
AU - Guloy, A. M.
AU - Chu, C. W.
AU - Arčon, D.
PY - 2011/8/11
Y1 - 2011/8/11
N2 - We report a 23Na and 75As nuclear magnetic resonance (NMR) investigation of NaxFeAs series (x=1, 0.9, 0.8) exhibiting a spin-density-wave (SDW) order below TSDW=45, 50, and 43 K for x=1, 0.9, 0.8, respectively, and a bulk superconductivity below Tc≈12 K for x=0.9. Below T SDW, a spin-lattice relaxation reveals the presence of gapless particle-hole excitations in the whole x range, meaning that a portion of the Fermi surface remains gapless. The superconducting fraction as deduced from the bulk susceptibility scales with this portion, while the SDW order parameter as deduced from the NMR linewidth scales inversely with it. The NMR line shape can only be reproduced assuming an incommensurate (IC) SDW. These findings qualitatively correspond to the mean-field models of competing interband magnetism and intraband superconductivity, which lead to an IC SDW order coexisting with superconductivity in part of the phase diagram.
AB - We report a 23Na and 75As nuclear magnetic resonance (NMR) investigation of NaxFeAs series (x=1, 0.9, 0.8) exhibiting a spin-density-wave (SDW) order below TSDW=45, 50, and 43 K for x=1, 0.9, 0.8, respectively, and a bulk superconductivity below Tc≈12 K for x=0.9. Below T SDW, a spin-lattice relaxation reveals the presence of gapless particle-hole excitations in the whole x range, meaning that a portion of the Fermi surface remains gapless. The superconducting fraction as deduced from the bulk susceptibility scales with this portion, while the SDW order parameter as deduced from the NMR linewidth scales inversely with it. The NMR line shape can only be reproduced assuming an incommensurate (IC) SDW. These findings qualitatively correspond to the mean-field models of competing interband magnetism and intraband superconductivity, which lead to an IC SDW order coexisting with superconductivity in part of the phase diagram.
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U2 - 10.1103/PhysRevB.84.054528
DO - 10.1103/PhysRevB.84.054528
M3 - Article
AN - SCOPUS:80052373262
SN - 1098-0121
VL - 84
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 5
M1 - 054528
ER -