Estimation for Entanglement Negativity of Free Fermions

Understand

In this letter we study the negativity of one dimensional free fermions.

• We derive the general form of the $\mathbb{Z}_{N}$ symmetric term in moments of the partial transposed (reduced) density matrix, which is an algebraic function of the end points of the system.
• Such a path integral turns out to be a convenient tool for making estimations for the negativity.