Thermalization of Gauge Theories from their Entanglement Spectrum

Using dual theories embedded into a larger unphysical Hilbert space along entanglement cuts, we study the entanglement structure of Z(2) lattice gauge theory in (2 + 1) spacetime dimensions. We demonstrate Li and Haldane's conjecture, and show consistency of the entanglement Hamiltonian with the BisognanoWichmann theorem. Studying nonequilibrium dynamics after a quench, we provide an extensive description of thermalization in Z(2) gauge theory which proceeds in a characteristic sequence: Maximization of the Schmidt rank and spreading of level repulsion at early times, self-similar evolution with scaling coefficients alpha = 0.8 +/- 0.2 and beta = 0.0 +/- 0.1 at intermediate times, and finally thermal saturation of the von Neumann entropy.