Entanglement spectra of the q-deformed Affleck-Kennedy-Lieb-Tasaki model and matrix product states

Understand

We exactly calculate the reduced density matrix of matrix product states (MPS).

• Our compact result enables one to perform analytic studies of entanglement in MPS.
• In particular, we consider the MPS ground states of two anisotropic spin chains.
• One is a q-deformed Affleck-Kennedy-Lieb-Tasaki (AKLT) model and the other is a general spin-1 quantum antiferromagnet with nearest-neighbor interactions.