Entanglement over the rainbow

Abstract

In one dimension the area law for the entanglement entropy is violated maximally by the ground state of a strong inhomogeneous spin chain, the so called concentric singlet phase (CSP), that looks like a rainbow connecting the two halves of the chain. In this paper we show that, in the weak inhomogeneity limit, the rainbow state is a thermofield double of a conformal field theory with a temperature proportional to the inhomogeneity parameter. This result suggests some relation of the CSP with black holes. Finally, we propose an extension of the model to higher dimensions.

References in corpus (4)

• Entanglement entropy of fermions in any dimension and the Widom conjecture
• Universal parity effects in the entanglement entropy of XX chains with open boundary conditions
• Hyperbolic Deformation on Quantum Lattice Hamiltonians
• Scaling Relation for Excitation Energy Under Hyperbolic Deformation