title: Boundary effects in the critical scaling of entanglement entropy in 1D systems.
abstract: We present exact diagonalization and density matrix renormalization group results for the entanglement entropy of critical spin-1/2 XXZ 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.
authors.affiliation: Department of Physics and Astronomy, University of British Columbia, Vancouver, B.C., V6T 1Z1 Canada.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Laflorencie
authors.forename: Erik S
authors.initials: ES
authors.lastname: Sørensen
authors.forename: Ming-Shyang
authors.initials: MS
authors.lastname: Chang
authors.forename: Ian
authors.initials: I
authors.lastname: Affleck