Fig. 1. Phase-transition diagram of ground-state entanglement with magnetic field under different anisotropic parameters γ _B and γ _J

Fig. 2. Critical magnetic field B_c as a function of anisotropy parameters γ _B and γ _J . (a) J =1, J _z =0 .

Fig. 3. Thermal entanglement as a function of external magnetic field B and anisotropy parameters γ _B . (a) J =1, γ _J =0 . 3, T =0 .

Fig. 4. Thermal entanglement as a function of magnetic field B under different coupling constants J _z . (a) J =1, γ _J =0 . 3, γ _B =0

Fig. 5. Thermal entanglementas a function of temperature T under different coupling constants J _z . (a) J =1, γ _J =0 . 3, γ _B =0