Edge-entanglement spectrum correspondence in a nonchiral topological phase and Kramers-Wannier duality

Understand

In a system with chiral topological order, there is a remarkable correspondence between the edge and entanglement spectra: the low-energy spectrum of the system in the presence of a physical edge coincides with the lowest part of the entanglement spectrum (ES) across a virtual cut of the system, up to rescaling and shifting.

• In this paper, we explore whether the edge-ES correspondence extends to nonchiral topological phases.
• Specifically, we consider the Wen-plaquette model which has Z_2 topological order.
• The unperturbed model displays an exact correspondence: both the edge and entanglement spectra within each topological sector a (a = 1,...,4) are flat and equally degenerate.