Figure 1
From: A duality principle for the multi-block entanglement entropy of free fermion systems
Difference ε between the exact value of the Rényi entropy, computed via Eq. (6) by numerical diagonalization of the correlation matrix (4), and its asymptotic approximation (23) for (a) γ x = γ p = 1/2 and (b) γ x = 1/8, γ p = 1/4. In panel (a) we have shown the cases (bottom to top) α = 3/5, 2/3, 3/4, 1 (von Neumann entropy) and α = 2 (inset), while panel (b) depicts the cases α = 2, 5/2, 3 (bottom to top, with the horizontal axis displaced respectively by 0.013 and 0.035 in the last two cases to avoid overlap). The solid red lines represent the curves providing the best fits of the data to the laws aN −2 (main panel (a)) and aN −2/αcos(2πγ x γ p N) (inset of panel (a) and panel (b)).
