Superlattice Quantum Critical Point in the Cubic Metal (Ca/Sr)3Ir4Sn13
L E Klintberg, S W Goh, P L Alireza, P J Saines, D A Tompsett, P W Logg, J Yan, B Chen, K Yoshimura and F M Grosche
Phys Rev Lett 109, 237008 (2012)
We show that the quasi-skutterudite superconductor Sr3Ir4Sn13 undergoes a structural transition from a simple cubic parent structure, the I phase, to a superlattice variant, the I′ phase, which has a lattice parameter twice that of the high temperature phase. We argue that the superlattice distortion is associated with a charge density wave transition of the conduction electron system and demonstrate that the superlattice transition temperature T* can be suppressed to zero by combining chemical and physical pressure. This enables the first comprehensive investigation of a superlattice quantum phase transition and its interplay with superconductivity in a cubic charge density wave system.