title: Violation of the entanglement area law in bosonic systems with Bose surfaces: possible application to Bose metals.
abstract: We show the violation of the entanglement area law for bosonic systems with Bose surfaces. For bosonic systems with gapless factorized energy dispersions on an N(d) Cartesian lattice in d dimensions, e.g., the exciton Bose liquid in two dimensions, we explicitly show that a belt subsystem with width L preserving translational symmetry along d-1 Cartesian axes has leading entanglement entropy (N(d-1)/3)lnL. Using this result, the strong subadditivity inequality, and lattice symmetries, we bound the entanglement entropy of a rectangular subsystem from below and above showing a logarithmic violation of the area law. For subsystems with a single flat boundary, we also bound the entanglement entropy from below showing a logarithmic violation, and argue that the entanglement entropy of subsystems with arbitrary smooth boundaries are similarly bounded.
authors: National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA.
authors: Hsin-Hua
authors: HH
authors: Lai
authors: Kun
authors: K
authors: Yang
authors: N E
authors: NE
authors: Bonesteel