论文标题
CERH $ _ {2} $的低温热电导率为$ _ {2} $
Low-Temperature Thermal Conductivity of CeRh$_{2}$As$_{2}$
论文作者
论文摘要
CERH $ _2 $ AS $ _2 $是一种罕见的非常规的超导体（$ T_C = 0.26 $ K），其特征是磁场的两个相邻超导阶段$ h \ h \ h \ parallel c $ - 平行C $轴 - 四方晶体结构。还报道了抗磁磁性顺序，四极密度波（$ t_0 = 0.4 $ k）以及该材料与量子关键点的接近度：目前正在讨论这些现象与超导性的这些现象的共存。在这里，我们在CERH $ _2 $的单个晶体上介绍了热电阻率和电阻率测量值，为$ _2 $在60 mk至200 K之间以及磁场（$ h \ \ parallel C $）之间，最多为8吨。我们在低$ t $上的测量值验证了Wiedemann-Franz在错误栏中的Wiedemann-Franz Law。导热率$κ（t）$的$ t依赖性显示出明显的下降$ t_c $，这也是依赖于场的，因此被解释为超导性的签名。但是，在预期的过渡温度下，$κ（t）$中较大的残余电阻率和缺乏尖锐的异常，这清楚地表明，需要更高纯度的样品才能获得有关超导间隙结构的更多信息。
CeRh$_2$As$_2$ is a rare unconventional superconductor ($T_c=0.26$ K) characterized by two adjacent superconducting phases for a magnetic field $H \parallel c$-axis of the tetragonal crystal structure. Antiferromagnetic order, quadrupole-density-wave order ($T_0 = 0.4$ K) and the proximity of this material to a quantum-critical point have also been reported: The coexistence of these phenomena with superconductivity is currently under discussion. Here, we present thermal conductivity and electrical resistivity measurements on a single crystal of CeRh$_2$As$_2$ between 60 mK and 200 K and in magnetic fields ($H \parallel c$) up to 8 T. Our measurements at low $T$ verify the Wiedemann-Franz law within the error bars. The $T$ dependence of the thermal conductivity $κ(T)$ shows a pronounced drop below $T_c$ which is also field dependent and thus interpreted as the signature of superconductivity. However, the large residual resistivity and the lack of sharp anomalies in $κ(T)$ at the expected transition temperatures clearly indicate that samples of much higher purity are required to gain more information about the superconducting gap structure.
