visualizations/ft.md

\begin{align*} ground state is two-fold degenerate, and when (B > \text{Bump}) the ground state becomes non-degenerate and the corre- \ spending wave function is given by \ \begin{equation} \left[| \text{voltage} \rangle = - \frac{1}{\sqrt{2}}| \text{1} \rangle, \end{equation} \end{align*} which is obviously of no entanglement. Then, the ground- state negativity forms a plateau when (B < \text{Bump}). The jump of negativity at (B = \text{Bump}) is due to the level crossing. For instance, for (N = 4), there are two level crossings, and the entanglement displays two jumps.