^{31}P and ^{75}As NMR evidence for a residual density of states at zero energy in superconducting BaFe_{2}(As_{0.67}P_{0.33})_{2}
^{31}P and ^{75}As NMR evidence for a residual density of states at zero energy in superconducting BaFe_{2}(As_{0.67}P_{0.33})_{2}
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DOI：
10.1103/physrevb.81.020503
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发表时间：
2009-08
影响因子：
3.7
通讯作者：
Y. Nakai;T. Iye;S. Kitagawa;K. Ishida;S. Kasahara;T. Shibauchi;Y. Matsuda;T. Terashima
中科院分区：
文献类型：
--
作者：
Y. Nakai;T. Iye;S. Kitagawa;K. Ishida;S. Kasahara;T. Shibauchi;Y. Matsuda;T. Terashima
$^{31}\text{P}$ and $^{75}\text{A}\text{s}$ NMR measurements were performed in superconducting ${\text{BaFe}}_{2}{({\text{As}}_{0.67}{\text{P}}_{0.33})}_{2}$ with ${T}_{c}=30\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. The nuclear-spin-lattice relaxation rate ${T\phantom{\rule{0.1em}{0ex}}}_{1}^{\ensuremath{-}1}$ and the Knight shift in the normal state indicate the development of antiferromagnetic fluctuations, and ${T\phantom{\rule{0.1em}{0ex}}}_{1}^{\ensuremath{-}1}$ in the superconducting (SC) state decreases without a coherence peak just below ${T}_{c}$, as observed in $({\text{Ba}}_{1\ensuremath{-}x}{\text{K}}_{x}){\text{Fe}}_{2}{\text{As}}_{2}$. In contrast to other iron arsenide superconductors, the ${T\phantom{\rule{0.1em}{0ex}}}_{1}^{\ensuremath{-}1}\ensuremath{\propto}T$ 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 ${\text{BaFe}}_{2}{({\text{As}}_{1\ensuremath{-}x}{\text{P}}_{x})}_{2}$ despite a comparable ${T}_{c}$ value, an analogous phase diagram, and similar Fermi surfaces to $({\text{Ba}}_{1\ensuremath{-}x}{\text{K}}_{x}){\text{Fe}}_{2}{\text{As}}_{2}$.
$^{31}\text{P}$ and $^{75}\text{A}\text{s}$ NMR measurements were performed in superconducting ${\text{BaFe}}_{2}{({\text{As}}_{0.67}{\text{P}}_{0.33})}_{2}$ with ${T}_{c}=30\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. The nuclear-spin-lattice relaxation rate ${T\phantom{\rule{0.1em}{0ex}}}_{1}^{\ensuremath{-}1}$ and the Knight shift in the normal state indicate the development of antiferromagnetic fluctuations, and ${T\phantom{\rule{0.1em}{0ex}}}_{1}^{\ensuremath{-}1}$ in the superconducting (SC) state decreases without a coherence peak just below ${T}_{c}$, as observed in $({\text{Ba}}_{1\ensuremath{-}x}{\text{K}}_{x}){\text{Fe}}_{2}{\text{As}}_{2}$. In contrast to other iron arsenide superconductors, the ${T\phantom{\rule{0.1em}{0ex}}}_{1}^{\ensuremath{-}1}\ensuremath{\propto}T$ 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 ${\text{BaFe}}_{2}{({\text{As}}_{1\ensuremath{-}x}{\text{P}}_{x})}_{2}$ despite a comparable ${T}_{c}$ value, an analogous phase diagram, and similar Fermi surfaces to $({\text{Ba}}_{1\ensuremath{-}x}{\text{K}}_{x}){\text{Fe}}_{2}{\text{As}}_{2}$.