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arXiv · 2004.03111

Evolution of charge density wave order and superconductivity under pressure in LaPt$_2$Si$_2$

B. Shen·F. Du·R. Li·A. Thamizhavel·M. Smidman·Z. Y. Nie·S. S. Luo·T. Le·Z. Hossain·H. Q. Yuan
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Abstract

We report measurements of the electrical resistivity and ac magnetic susceptibility of single crystalline LaPt$_2$Si$_2$ under pressure, in order to investigate the interplay of superconductivity and CDW order. LaPt$_2$Si$_2$ exhibits a first order phase transition from a tetragonal to orthorhombic structure, accompanied by the onset of CDW order below $T_{\rm{CDW}}$ = 76 K, while superconductivity occurs at a lower temperature of $T_{\rm{c}}$ = 1.87 K. We find that the application of pressure initially suppresses the CDW transition, but enhances $T_{\rm{c}}$. At pressures above 2.4 GPa, CDW order vanishes, while both $T_{\rm{c}}$ and the resistivity $A$-coefficient reach a maximum value around this pressure. Our results suggest that the occurrence of a superconducting dome can be accounted for within the framework of BCS theory, where there is a maximum in the density of states upon the closure of the CDW gap.

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B. Shen, F. Du, R. Li, A. Thamizhavel, M. Smidman, Z. Y. Nie, S. S. Luo, T. Le, Z. Hossain, H. Q. Yuan. 2020-04-07. Evolution of charge density wave order and superconductivity under pressure in LaPt$_2$Si$_2$. https://doi.org/10.1103/physrevb.101.144501

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