Absence of logarithmic enhancement in the entanglement scaling of free fermions on folded cubes

Abstract

This study investigates the scaling behavior of the ground-state entanglement entropy in a model of free fermions on folded cubes. An analytical expression is derived in the large-diameter limit, revealing a strict adherence to the area law. The absence of the logarithmic enhancement expected for free fermions is explained using a decomposition of folded cubes in chains based on its Terwilliger algebra and \(\mathfrak{so}(3)_{-1}\). The entanglement Hamiltonian and its relation to Heun operators are also investigated.