A method of detecting magnetic interaction in the quantum spin liquid material NaYbSe2 through magnetic dilution

Quantum spin liquid (QSL) holds important application prospects in the realm of quantum computing, and the precise knowledge of magnetic interaction is essential for understanding the magnetism of QSL materials. Here, we report a method of detecting the magnetic interactions in the triangular-lattice QSL candidate NaYbSe2 through magnetic dilution. The single crystals of NaYb0.02Lu0.98Se2 were grown and they maintain the same crystal structure (space group R-3m) as NaYbSe2. Magnetization steps were observed at Hc = 31 kOe for H//ab and Hc = 53 kOe for H//c in the magnetization curves at 0.39 K, suggesting the formation of nearly isolated antiferromagnetic Yb–Yb dimers. Fitting the dimer magnetization curves yields anisotropic exchange parameters of J⊥/kB ≈ −6.15 K and Jz/kB ≈ −2.14 K and an average exchange of Jav/kB = −6.44 K. Since NaYb0.02Lu0.98Se2 exhibits similar g-factor anisotropy, comparable Yb–Yb bond length, and Yb–Se–Yb superexchange angle to NaYbSe2, these exchange parameters can be viewed as the values of NaYbSe2.