The Mott transition is one of the fundamental issues in condensed matter physics, especially in the system with antiferromagnetic long-range order. However the Mott transition in quantum spin liquid (QSL) systems without long-range order is rare. Here we report the observation of the pressure-induced insulator to metal transition followed by the emergence of superconductivity in the QSL candidate NaYbSe2 with triangular lattice of 4f Yb$_3^+$ ions. Detail analysis of transport properties at metallic state shows an evolution from non-Fermi liquid to Fermi liquid behavior when approaching the vicinity of superconductivity. An irreversible structure phase transition occurs around 11 GPa is revealed by the X-ray diffraction and Raman spectrum. These results shed light on the Mott transition and superconductivity in the QSL systems.

中文翻译：

---

量子自旋液体候选 NaYbSe2 中的莫特跃迁和超导性

莫特跃迁是凝聚态物理学中的基本问题之一，尤其是在具有反铁磁长程有序的系统中。然而，没有长程有序的量子自旋液体 (QSL) 系统中的莫特跃迁是罕见的。在这里，我们报告了对压力诱导绝缘体到金属转变的观察结果，随后在具有 4f Yb$_3^+$ 离子三角形晶格的 QSL 候选 NaYbSe2 中出现了超导性。金属态传输特性的详细分析表明，当接近超导附近时，非费米液体行为会演变为费米液体行为。X 射线衍射和拉曼光谱揭示了在 11 GPa 附近发生的不可逆结构相变。这些结果阐明了 QSL 系统中的莫特跃迁和超导性。