Mott Transition and Superconductivity in Quantum Spin Liquid Candidate NaYbSe<sub>2</sub>
Ya-Ting Jia, Chun-Sheng Gong, Yi-Xuan Liu, Jian-Fa Zhao, Cheng Dong, Guang-Yang Dai, Xiao-Dong Li, He-Chang Lei, Run-Ze Yu, Guang-Ming Zhang, Chang-Qing Jin
Abstract
The Mott transition is one of the fundamental issues in condensed matter physics, especially in the system with antiferromagnetic long-range order. However, such a transition is rare in quantum spin liquid (QSL) systems without long-range order. Here we report the experimental pressure-induced insulator to metal transition followed by the emergence of superconductivity in the QSL candidate NaYbSe 2 with a triangular lattice of 4 f Yb 3+ ions. Detail analysis of transport properties in 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, which is revealed by the x-ray diffraction. These results shed light on the Mott transition in the QSL systems.