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

Abstract

Topological 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.

Intersecting topological nodal ring and nodal wall states in superhard superconductor FeB4

“…Recently, researchers have also been keen to develop materials that feature both topological nodal lines (NLs) and superconducting states. Thus far, a handful of known TMs with a one-dimensional (1D) TE accompanied by superconductivity have been predicted, including NaAlSi 15 , [Ti/Mg]Bi2 16,17 , [Sn/Pb]TaSe2 18,19 , SrAs3 20,21 , and InxTaS2 22 . To the best of our knowledge, TMs with a 2D TE, namely, nodal wall (also called nodal surface) [23][24][25] states and possible superconductivity, have not been analyzed by researchers.…”