title: Ambient pressure structural quantum critical point in the phase diagram of (Ca(x)Sr(1-x))(3)Rh(4)Sn(13).
abstract: 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.
authors: 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.
authors: S K
authors: SK
authors: Goh
authors: Department of Chemistry, Imperial College London, South Kensington SW7 2AZ, United Kingdom.
authors: D A
authors: DA
authors: Tompsett
authors: Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford OX1 3QR, United Kingdom.
authors: P J
authors: PJ
authors: Saines
authors: Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom.
authors: H C
authors: HC
authors: Chang
authors: Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
authors: T
authors: T
authors: Matsumoto
authors: Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
authors: M
authors: M
authors: Imai
authors: Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
authors: K
authors: K
authors: Yoshimura
authors: Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom.
authors: F M
authors: FM
authors: Grosche