A brief review of the physical properties of charge density wave superconductor LaPt2Si2

Abstract

Abstract The study of materials with multiple phases, such as superconductivity (SC) coexisting with charge density wave (CDW) or spin density wave (SDW) instability, attracts considerable interest from the condensed matter research community. The CDW superconductors started drawing in heaps of attention soon after the discovery of CDW instability in high-T c cuprates, where understanding the underlying superconducting mechanism of the latter may turn out to be path-breaking for the discovery of room temperature SC. Understanding the pairing mechanism of high-T c superconductors necessitates less complex systems and this makes searching for CDW superconductors all the more important. Such systems avoid the additional complexity in contrast to the well-sought after Fe-based superconductors, which show more competing orders like SDW, nematicity and SC. RPt2Si2 (R = La, Pr, Eu) is a recently discovered series of materials, members of which crystallizes in CaBe2Ge2 type structure which has a close resemblance to the ThCr2Si2 type structure commonly found in pnictide-122 superconductors. This review is focused on LaPt2Si2, which undergoes a structural transition from high-temperature tetragonal to low-temperature orthorhombic structure, accompanied by a CDW transition around 112 K, which is then followed by a superconducting transition below 1.8 K. We discuss the physical properties of single crystal and polycrystalline LaPt2Si2 samples. Additionally, we present the results of transport and ac susceptibility measurements under external hydrostatic pressure to map out the temperature-pressure phase diagram of LaPt2Si2.