Bipartite entanglement of a two-qubit system with anisotropic couplings under nonuniform magnetic fields

This paper investigates bipartite entanglement of a two-qubit systemwith anisotropic couplings under an inhomogeneous magnetic field.This work is mainly to investigate the characteristics of aHeisenberg XYZ chain and obtains some meaningful results. By theconcept of negativity, it finds that the inhomogeneity of magneticfield may induce entanglement and the critical magnetic field isindependent of J_z. The inhomogeneous magnetic field canincrease the value of critical magnetic field B_c. It also findsthat the magnetic field not only suppresses the entanglement butalso can induce it to revival for some time.