Fractional Quantum Hall Effect States on a Torus show a Liquid Insulator   Direct Transition
  From the Fractional Quantum Hall Effect States on a torus with filling factor nu = 1/p, p odd, we found that for small values of nu such states describe triangular Wigner crystals which are stable configurations. Therefore, the insulator phase of the two-dimensional electron system can be described with the same wave function that the liquid phase, and the incompressible liquid freezes (or the Wigner crystal melts) without any quantum transition between states, thus the system phase changes by means of a direct transition. We found at least one stable configuration of a Wigner crystal with F = 3 electrons for cell and we investigate the behavior of the crystal when the lengths ratio Ly/Lx changes. 
Jaime Montes