Synthesis and anisotropic magnetism in quantum spin liquid candidates AYbSe2 (A = K and Rb)

Abstract

The quantum spin liquid (QSL) state in rare-earth triangular lattices has attracted much attention recently due to its potential application in quantum computing and communication. Here, we report the single-crystal growth synthesis, crystal structure characterizations, and magnetic properties of AYbSe2 (A = K and Rb) compounds. The x-ray diffraction analysis shows that AYbSe2 (A = K and Rb) crystallizes in a trigonal space group, R-3m (No. 166) with Z = 3. AYbSe2 possesses a two-dimensional (2D) Yb–Se–Yb layered structure formed by edged-shared YbSe6 octahedra. The magnetic properties are highly anisotropic for both title compounds, and no long-range order is found down to 0.4 K, revealing the possible QSL ground state in these compounds. The isothermal magnetization exhibits a one-third magnetization plateau when the magnetic fields are applied in the ab-plane. Heat capacity is performed along both ab-plane and c axis and features the characteristic dome for triangular magnetic lattice compounds as a function of magnetic fields. Due to the change in the interlayer and intralayer distance of Yb3+, the dome shifts to low fields from KYbSe2 to RbYbSe2. All these results indicate that the AYbSe2 family presents unique frustrated magnetism close to the possible QSL and noncollinear spin states.