论文标题
Cecoin的超低温度NMR $ _5 $
Ultralow temperature NMR of CeCoIn$_5$
论文作者
论文摘要
我们已经执行了$^{59} $ co nmr cecoin $ _5 $的测量值，以降低到超高温度。我们发现，自旋回波强度的温度依赖性很好地衡量了样品温度，从而使我们能够确定脉冲条件，而不是通过NMR脉冲将样品加热到超高温度。从沿$ c $轴进行5 t的纵向放松时间（$ t_1 $）的测量值，在20 mk处观察到$ 1/t_1t $的明显峰值，这意味着如最近的量子振荡尺寸所建议的磁顺序外观[H. Shishido {\ it等}，物理。莱特牧师。 {\ bf 120}，177201（2018）]。另一方面，NMR频谱没有显示20 mk以下的变化。此外，与量子振荡的结果相反，$ 1/t_1 t $的峰值在6和8 t消失。我们讨论一个反铁磁性状态，片刻位于$ a-$ b $ phlaper中可能是5 t $ 1/t_1 t $的峰值。
We have performed $^{59}$Co NMR measurements of CeCoIn$_5$ down to ultralow temperatures. We find that the temperature dependence of the spin-echo intensity provides a good measure of the sample temperature, enabling us to determine a pulse condition not heating up the sample by the NMR pulses down to ultralow temperatures. From the longitudinal relaxation time ($T_1$) measurements at 5 T applied along the $c$ axis, a pronounced peak in $1/T_1T$ is observed at 20 mK, implying an appearance of magnetic order as suggested by the recent quantum oscillation measurements [H. Shishido {\it et al.}, Phys. Rev. Lett. {\bf 120}, 177201 (2018)]. On the other hand, the NMR spectrum shows no change below 20 mK. Moreover, the peak in $1/T_1 T$ disappears at 6 and 8 T in contrast to the results of the quantum oscillation. We discuss that an antiferromagnetic state with a moment lying in the $a$--$b$ plane can be a possible origin for the peak in $1/T_1 T$ at 5 T.
