Entanglement spectrum and entropy of the 1D quantum q-state clock model via exact diagonalization and density matrix renormalization group

This work studies the entanglement spectrum and Rényi entropy of the one-dimensional quantum q-state clock model for q = 2 to q = 6 using exact diagonalization (ED) and the density matrix renormalization group (DMRG), implemented with the conserved modular charge k for symmetry resolution. For all q values, the entanglement spectra display a mapping between sectors labeled by k and q-k, with the ground state of the entanglement Hamiltonian consistently located in the neutral-charge sector k = 0.