One-dimensional spin-one Heisenberg antiferromagnet with single-ion anisotropy in a magnetic field: Schwinger boson theory

The one-dimensional spin-one Heisenberg antiferromagnet with single-ion anisotropy in the presence of the applied magnetic field is explored in terms of the Schwinger boson mean-field theory. The temperature and anisotropy dependences of the specific heat, the susceptibility and the magnetization are thoroughly discussed. New features of the specific heat as a function of temperature as well as anisotropy are found. A transition from an antiferromagnetic phase to a spin-canting phase is observed, and meanwhile, a schematic phase diagram is proposed.