Center for Materials Theory, Rutgers University, Piscataway, New Jersey 08854, USA.
Department of Physics and Astronomy, Iowa State University, 12 Physics Hall, Ames, Iowa 50011, USA.
Phys Rev Lett. 2015 Jan 16;114(2):027002. doi: 10.1103/PhysRevLett.114.027002. Epub 2015 Jan 15.
The recent observation of fully gapped superconductivity in Yb doped CeCoIn_{5} poses a paradox, for the disappearance of nodes suggests that they are accidental, yet d-wave symmetry with protected nodes is well established by experiment. Here, we show that composite pairing provides a natural resolution: in this scenario, Yb doping drives a Lifshitz transition of the nodal Fermi surface, forming a fully gapped d-wave molecular superfluid of composite pairs. The T^{4} dependence of the penetration depth associated with the sound mode of this condensate is in accordance with observation.
最近在 Yb 掺杂 CeCoIn_{5}中观察到完全带隙超导现象，这构成了一个悖论，因为节点的消失表明它们是偶然的，但实验已经很好地确立了具有保护节点的 d 波对称性。在这里，我们表明复合配对提供了一个自然的解决方案：在这种情况下，Yb 掺杂驱动节点费米面的 Lifshitz 转变，形成完全带隙的 d 波分子超流体的复合对。与这种凝聚体的声波模式相关的穿透深度的 T^{4}依赖性与观察结果一致。
