Theory of the quantum-Hall liquid to insulator transition

We study the quantum-Hall liquid to insulator transition in the two-dimensional electron gas, both where the disorder is large, and where it is small so that the insulating state has moderate-range Wigner-crystal order. We use the Chern-Simons Ginzburg-Landau theory to relate this transition to the transition between quantum-Hall liquids. © 1991 The American Physical Society.