在平行磁场中测量超导 Sr2RuO4 的 101Ru 奈特位移

Measurement of the 101Ru-Knight shift of superconducting Sr2RuO4 in a parallel magnetic field.

作者信息

Murakawa H, Ishida K, Kitagawa K, Mao Z Q, Maeno Y

机构信息

Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.

出版信息

Phys Rev Lett. 2004 Oct 15;93(16):167004. doi: 10.1103/PhysRevLett.93.167004.

DOI:10.1103/PhysRevLett.93.167004

PMID:15525023

Abstract

101Ru-Knight shift (101K) in the spin-triplet superconductor Sr2RuO4 was measured under magnetic fields parallel to the c axis (perpendicular to the RuO2 plane), which is the promising superconducting (SC) d-vector direction in a zero field. We succeeded in measuring K(c) in the field range from 200 to 1200 Oe and at temperatures down to 80 mK, using nuclear-quadrupole-resonance spectra. We found that (101)K(c) is invariant with respect to the field and temperature on passing through H(c2) and T(c) above 200 Oe. This indicates that the spin susceptibility along the c axis does not change in the SC state, at least, in the field greater than 200 Oe. The results imply that the SC d vector is in the RuO2 plane when the magnetic field is applied to the c axis.

摘要

在与c轴平行（垂直于RuO₂平面）的磁场下测量了自旋三重态超导体Sr₂RuO₄中的¹⁰¹Ru-奈特位移（¹⁰¹K），在零场中这是很有前景的超导（SC）d矢量方向。我们利用核四极共振光谱成功地在200至1200奥斯特的磁场范围内以及低至80毫开尔文的温度下测量了K(c)。我们发现，当磁场高于200奥斯特且温度高于Tc时，(¹⁰¹)K(c)在通过H(c2)和Tc时与磁场和温度无关。这表明，至少在大于200奥斯特的磁场中，超导态下沿c轴的自旋磁化率不变。结果表明，当磁场施加于c轴时，超导d矢量位于RuO₂平面内。