Continuous quantum phase transition between two topologically distinct valence bond solid states associated with the same spin value.

We propose a one-dimensional quantum Heienberg spin-2 chain, which exhibits two topologically distinct valence bond solid states in two different solvable limits. We then construct the phase diagram and study the quantum phase transition between these two states using infinite time evolving block decimation algorithms. From the scaling relation between the entanglement entropy and the correlation length, we determine that the central charge for the underlying critical conformal field theory is around two. [ABSTRACT FROM AUTHOR]