Crystal growth and magnetic properties of quantum spin liquid candidate KErTe2 * *Project supported by the National Key Research and Development Program of China (Grant Nos. 2017YFA0302904 and 2016YFA0300504), the National Natural Science Foundation of China (Grant Nos. U1932215 and 11774419), the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB33010100), and Postdoctoral Science Foundation of

Abstract

Recently rare-earth chalcogenides have been revealed as a family of quantum spin liquid (QSL) candidates hosting a large number of members. In this paper we report the crystal growth and magnetic measurements of KErTe2, which is the first member of telluride in the family. Compared to its cousins of oxides, sulfides and selenides, KErTe2 retains the high symmetry of and Er3+ ions still sit on a perfect triangular lattice. The separation between adjacent magnetic layers is expectedly increased, which further enhances the two dimensionality of the spin system. Specific heat and magnetic susceptibility measurements on KErTe2 single crystals reveal no structural and magnetic transition down to 1.8 K. Most interestingly, the absorption spectrum shows that the charge gap of KErTe2 is roughly 0.93±0.35 eV, which is the smallest among all the reported members in the family. This immediately invokes the interest towards metallization even superconductivity using the compound.