Abstract
We present exact diagonalization and density matrix renormalization group results for the entanglement entropy of critical spin- chains. We find that open boundary conditions induce an alternating term in both the energy density and the entanglement entropy which are approximately proportional, decaying away from the boundary with a power law. The power varies with anisotropy along the critical line and is corrected by a logarithmic factor, which we calculate analytically, at the isotropic point. A heuristic resonating valence bond explanation is suggested.
- Received 19 December 2005
DOI:https://doi.org/10.1103/PhysRevLett.96.100603
©2006 American Physical Society