An Intuitive Understanding of the Spin Excitations of a 1D Antiferromagnet

Antiferromagnetic Heisenberg spin model is one of the basic models in quantum magnetism. Although in two- and three-dimensional world its ground state has a classical order, in one dimension (chains) there is no long-range order and the exact form of the ground state is provided by a rather complex Bethe Ansatz. Even more intricate are the low energy magnetic excitations of a spin chain — the notorious spinons, carrying fractional quantum numbers. In this poster we show an alternative approach to the ground state as well as the low-lying excitations of the one-dimensional Heisenberg antiferromagnet, which, although approximate, gives a more physically intuitive picture than the exact Bethe Ansatz solution.