On Ground State Degeneracy of <i>Z</i><sub>2</sub> Symmetric Quantum Spin Models
Taku Matsui
Tokyo Metropolitan University, Japan

Abstract
We consider a class of _Z_2 symmetric quantum spin Hamiltonians. Anisotropic spin 1/2 Heisenberg models are typical examples. Proof of groound state degeneracy (_Z_2 symmetry breaking), construction of pure gournd states are given in a systematic way.
Cite this article
Taku Matsui, On Ground State Degeneracy of <i>Z</i><sub>2</sub> Symmetric Quantum Spin Models. Publ. Res. Inst. Math. Sci. 27 (1991), no. 4, pp. 657–679
DOI 10.2977/PRIMS/1195169424