Thermodynamic symmetry resolved entanglement entropies in integrable systems

We develop a general approach to compute the symmetry-resolved Renyi and von Neumann entanglement entropies (SREE) of thermodynamic macrostates in interacting integrable systems. Our method is based on a combination of the thermodynamic Bethe ansatz and the Gartner-Ellis theorem from large deviation theory. We derive an explicit simple formula for the von Neumann SREE, which we show to coincide with the thermodynamic Yang-Yang entropy of an effective macrostate determined by the charge sector. Focusing on the XXZ Heisenberg spin chain, we test our result against iTEBD calculations for thermal states, finding good agreement. As an application, we provide analytic predictions for the asymptotic value of the SREE following a quantum quench.

Automated summary

This article presents a general approach to compute the symmetry-resolved Renyi and von Neumann entanglement entropies of thermodynamic macrostates in interacting integrable systems. The method combines the thermodynamic Bethe ansatz with the Gartner-Ellis theorem and derives a simple formula for the von Neumann entropy. The results are tested on the XXZ Heisenberg spin chain with good agreement.