Observation of superconductivity and its enhancement at the charge density wave critical point in LaAgSb${}_2$

Abstract

We discover superconductivity (SC) in LaAgSb${}_2$ at ambient pressure and its close correlation with a charge density wave (CDW) under pressure. The superconducting transition temperature ($T_c$) exhibits a sharp peak at the CDW critical pressure of 3.2 GPa. We demonstrate that the carriers inhabiting the Sb-square net is crucial not only in the formation of CDW but also in SC for their relatively strong electron-phonon coupling (EPC). Furthermore, theoretical EPC strength in pristine LaAgSb${}_2$ cannot explain the observed peak with $T_c\sim 1$ K, which indicates that an additional mechanism reinforces SC only around the CDW critical pressure.

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Cited by in corpus (3)

• Coexistence of Dirac fermion and charge density wave in square-net-based semimetal LaAuSb2
• Phonon-mediated superconductivity in the Sb-square-net compound LaCuSb${}_2$
• Effects of physical and chemical pressure on charge density wave transitions in LaAg1-xAuxSb2 single crystals