Fig. 5: Entanglement fluctuations of XXZ model.
We perform long-time simulations for this model to study the mesoscopic fluctuations in entanglement evolution. Initially, the system is at an unpolarized random state. a Main panel: The statistical distribution of entanglement entropy for different ratios of LA/L. Inset: The large deviation probability P(∣S−〈S〉∣≥ϵ), with upper (squares) and lower (circles) tail respectively, is well fitted by Eq. (2) (dashed lines). Δ = 0.1. b Calculating the matrix elements \({({\rho }_{A0})}_{IJ}\) numerically, it is confirmed that ρA0 is proportional to the unit matrix. c The simulated Var(S) (symbols) follows the scaling law described by the second line of Eq. (1) (dashed lines). In the main panel (inset), LA (L) is fixed. d For different Δ and small LA/L, simulations show that Var(S) ∝ Var(S2).
