125Te-NMR Study on a Single Crystal of Heavy Fermion Superconductor UTe2
125Te-NMR Study on a Single Crystal of Heavy Fermion Superconductor UTe2
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DOI：
10.7566/jpsj.88.073701
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发表时间：
2019-07-15
影响因子：
1.7
通讯作者：
Aoki, Dai
中科院分区：
文献类型：
--
作者：
Tokunaga, Yo;Sakai, Hironori;Aoki, Dai
本文报道了一种新发现的重费米子超导体UTe 2的Te-125 NMR研究结果。用单晶测量了Te-125核磁共振Knight位移K和自旋晶格弛豫速率1/T-1，场沿沿着三个正交晶轴。实验结果表明，在20 K以上的顺磁状态下，样品的静态磁化率（K）和动态磁化率（1/T-1）都具有中等的伊辛各向异性。然而，在20 K附近，我们观察到，当沿磁化的易磁化轴（= a轴）沿着施加场时，由于NMR自旋-自旋弛豫速率1/T-2的突然增强，NMR自旋回波信号突然损失。这种行为表明，在低于20 K的非常低的频率下，纵向磁波动沿着a轴的发展。
We report Te-125 NMR studies on a newly discovered heavy fermion superconductor UTe2. Using a single crystal, we have measured the Te-125 NMR Knight shift K and spin lattice relaxation rate 1/T-1 for fields along the three orthorhombic crystal axes. The data confirm a moderate Ising anisotropy for both the static (K) and dynamical susceptibilities (1/T-1) in the paramagnetic state above about 20K. Around 20K, however, we have observed a sudden loss of NMR spin-echo signal due to sudden enhancement of the NMR spin-spin relaxation rate 1/T-2, when the field is applied along the easy axis of magnetization (= a-axis). This behavior suggests the development of longitudinal magnetic fluctuations along the a-axis at very low frequencies below 20 K.