Deriving quantum spin model for a zigzag-chain ytterbium magnet with anisotropic exchange interactions

Hidehiro Saito, Hiroki Nakai, Chisa Hotta

We derive a quantum spin Hamiltonian of the spin-1/2 zigzag chain realized in a rare earth ytterbium-based magnetic insulator, YbCuS2. This material undergoes a transition at 0.95K…