Geometric entanglement for quantum critical spin chains belonging to the Ising and three-state Potts universality classes

The leading finite-size correction to the geometric entanglement per lattice site is investigated for the antiferromagnetic–ferromagnetic alternating Heisenberg model, quantum three-state Potts model in a transverse field and a spin-1/2 spin chain with the competing two-spin and three-spin interactions at criticality, belonging to the Ising and three-state Potts universality classes with the central charge c=1/2c=1/2 and c=4/5c=4/5, respectively. Our results demonstrate that the leading finite-size correction coefficient is essentially the celebrated Affleck–Ludwig boundary entropy corresponding to a conformally invariant boundary condition, which in turn depends on the period of the translation-invariant separable states.

► The quantum critical points are identified for three models by the von Neumann entropy approach.
► Establish the connection between the leading finite-size correction coefficient and g factor.
► The leading finite-size correction coefficient depends on the period of the separable states.