On the entanglement entropy for a XY spin chain

Abstract

The entanglement entropy for the ground state of a XY spin chain is related to the corner transfer matrices of the triangular Ising model and expressed in closed form.

Figures (2)

• Figure 1: Portion of a triangular lattice forming the row transfer matrix T
• Figure 2: Construction of the reduced density matrix $\hat{\rho}$ from six triangular corner transfer matrices. Along the heavy line the lattice is cut open. The notation follows Ref. [13].