Goh S K, Tompsett D A, Saines P J, Chang H C, Matsumoto T, Imai M, Yoshimura K, Grosche F M
Department of Physics, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom.
Phys Rev Lett. 2015 Mar 6;114(9):097002. doi: 10.1103/PhysRevLett.114.097002. Epub 2015 Mar 4.
The quasiskutterudite superconductor Sr_{3}Rh_{4}Sn_{13} features a pronounced anomaly in electrical resistivity at T^{}∼138 K. We show that the anomaly is caused by a second-order structural transition, which can be tuned to 0 K by applying physical pressure and chemical pressure via the substitution of Ca for Sr. A broad superconducting dome is centered around the structural quantum critical point. Detailed analysis of the tuning parameter dependence of T^{} as well as insights from lattice dynamics calculations strongly support the existence of a structural quantum critical point at ambient pressure when the fraction of Ca is 0.9 (i.e., x_{c}=0.9). This establishes the (Ca_{x}Sr_{1-x}){3}Rh{4}Sn_{13} series as an important system for exploring the physics of structural quantum criticality without the need of applying high pressures.
类方钴矿超导体Sr₃Rh₄Sn₁₃在T* ∼ 138 K时电阻率出现明显异常。我们表明，该异常是由二级结构转变引起的，通过用Ca替代Sr施加物理压力和化学压力，可将其调至0 K。一个宽超导穹顶以结构量子临界点为中心。对T*的调谐参数依赖性的详细分析以及晶格动力学计算的见解有力地支持了在常压下当Ca的分数为0.9（即xc = 0.9）时存在结构量子临界点。这确立了(CaₓSr₁₋ₓ)₃Rh₄Sn₁₃系列作为无需施加高压即可探索结构量子临界物理的重要体系。
