Topological Quantum Phase Transition in One-dimensional Spin Chain

We construct a Hamiltonian between AKLT and SZH model for one-dimensional S = 2 spin chain, where a variable parameter $\alpha$ is introduced. The edge spin is boson-like for AKLT model ($\alpha=0$), while fermion-like for SZH model($\alpha = 1$). Due to this distinction, topological quantum phase transition is predicted, and is addressed by large-scale DMRG calculation.