Emerging Superconductivity and the Origin of Its Enhancement in Pressurized Topological Nodal‐Line Semimetal SrAs3

Abstract

AbstractTopological nodal‐line semimetal SrAs3 hosts a simple nodal loop on the verge of Fermi level without distracting trivial states, providing a good platform for further investigations of electronic quantum states. Here, a report on pressure‐driven superconductivity in SrAs3 single crystal is provided and the interplay between the crystal structure, electronic state, and superconductivity is clarified therein. The comprehensive high‐pressure experiments, i.e., synchrotron X‐ray diffraction, electrical transport, and Raman spectroscopy, consistently reveal a critical pressure Pc ≈ 25 GPa. Around Pc, a superconducting transition appears, concomitant with the formation of high‐pressure cubic Pm‐3m phase. Meanwhile, the superconducting transition temperature Tc and hole carrier density increase synchronously above Pc. This finding demonstrates that the emerging superconductivity in SrAs3 stems from the high‐pressure cubic phase on the one hand, and shows that the evolution of Tc(P) is intimately correlated with the enhanced density of states near the Fermi level on the other hand.