d-Wave Superconductivity in Antiferromagnetic Heavy-Fermion Compound UPd2Al3 –Evidence from27Al NMR/NQR Studies–
d-Wave Superconductivity in Antiferromagnetic Heavy-Fermion Compound UPd2Al3 –Evidence from27Al NMR/NQR Studies–
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反铁磁重费米子化合物 UPd2Al3 中的 d 波超导性 –来自 27Al NMR/NQR 研究的证据 –
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
F. Steglich
中科院分区：
文献类型：
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作者：
H. Tou;Y. Kitaoka;K. Asayama;C. Geibel;C. Schank;F. Steglich
用核四极共振（NQR）技术测量了高质量多晶UPd 2Al 3的核自旋晶格弛豫率27（1/T1），其记录Tc = 2K，迄今为止最宽的Al NQR线宽为12 kHz。27（1/T1）在0.18K以下服从T3定律，有力地证明了能隙沿费米面沿着消失.对27 Al在Tc以下的Knight位移的分析表明，各向异性的剩余Knight位移源于反铁磁态的f电子磁化率，而在Tc以下的各向同性减少则是由于超导的单线态配对性质. UPd 2Al 3中27（1/T1）和27 Al Knight位移的结果都可以用费米面上的能隙消失线表征的d波配对模型一致地再现。
The nuclear-spin-lattice relaxation rate, 27 (1/ T 1 ), of the high-quality polycrystalline UPd 2 Al 3 with a record T c =2 K and the narrowest Al NQR linewidth to date of 12 kHz has been measured in zero magnetic field by the NQR technique. 27 (1/ T 1 ) below T c has been found to obey the T 3 - law at least down to 0.18 K, giving strong evidence that the energy gap vanishes along lines on the Fermi surface. From the analysis of 27 Al Knight shift below T c , it is shown that the anisotropic residual Knight shift originates from the f -electron susceptibility in the antiferromagnetic state, whereas the isotropic reduction of the shift below T c is due to a singlet pairing nature of the superconductivity. Both the results of 27 (1/ T 1 ) and 27 Al Knight shift in UPd 2 Al 3 can be reproduced consistently by a d-wave pairing model characterized by lines of vanishing gap on the Fermi surface.