This is a study of the ground-state properties of the one-dimensional spin-s(12⩽s∞) anisotropic XYZ antiferromagnet in a magnetic field of arbitrary direction. It provides the first rigorous results for the general case of this model in non-zero field. By exact calculations we find the...

This is a study of magnetic-field effects on various zero-temperature properties of the one-dimensional S = 12 XY model with exchange alternation or anisotropy. Alternation and anisotropy in the interaction cause different types of spin ordering in the ground state, which in turn are responsible...