摘要
We report ^(121/123)Sb nuclear quadrupole resonance(NQR)and ^(51)V nuclear magnetic resonance(NMR)measurements on kagome metal CsV_(3)Sb_(5) with T_(c)=2.5 K.Both ^(51)V NMR spectra and ^(121/123)Sb NQR spectra split after a charge density wave(CDW)transition,which demonstrates a commensurate CDW state.The coexistence of the high temperature phase and the CDW phase between 91 K and 94 K manifests that it is a first-order phase transition.At low temperature,electric-field-gradient fluctuations diminish and magnetic fluctuations become dominant.Superconductivity emerges in the charge order state.Knight shift decreases and 1/T_(1)T shows a Hebel–Slichter coherence peak just below T_(c),indicating that CsV_(3)Sb_(5) is an s-wave superconductor.
作者
Chao Mu
Qiangwei Yin
Zhijun Tu
Chunsheng Gong
Hechang Lei
Zheng Li
Jianlin Luo
牟超;殷蔷薇;涂志俊;龚春生;雷和畅;李政;雒建林(Beijing National Laboratory for Condensed Matter Physics and Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100190,China;Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials&Micro-nano Devices,Renmin University of China,Beijing 100872,China;Songshan Lake Materials Laboratory,Dongguan 523808,China)
基金
Supported by the National Key Research and Development Program of China(Grant Nos.2017YFA0302901,2018YFE0202600,and 2016YFA0300504)
the National Natural Science Foundation of China(Grant Nos.11921004,11634015,11822412,and 11774423)
the Beijing Natural Science Foundation(Grant No.Z200005)
the Strategic Priority Research Program and Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(Grant No.XDB33010100).
