Figure 4: Quantum phase transition and topological degeneracy.
From: Fractional quantum Hall effect in the absence of Landau levels
The low-energy spectrum for lowest n states (n=1, ..., 20) as a function of U (with V=U) for a system with Ns=50. The dashed line marks the critical value Uc, at which the phase transition between a Fermi-liquid phase and the FQHE takes place.
