Physical Review
Linear Antiferromagnetic Chain
Sergio Rodríguez
Abstract
It is shown that a linear chain consisting of a large number of atoms of spin \textonehalf{} with nearest neighbor ferromagnetic or antiferromagnetic interactions is mathematically equivalent to a one-dimensional Fermi gas with two-body forces. This equivalence is used to construct a wave function for which the expectation value of the energy lies between the two approximations obtained by Hulth\'en. Also, a perturbation treatment is given which permits, in principle, to obtain the exact antiferromagnetic ground state.