Characterization of the quantized Hall insulator phase in the quantum critical regime

The conductivity σ and resistivity ρ tensors of the disordered Hofstadter model are mapped as functions of Fermi energy EF and temperature T in the quantum critical regime of the plateau-insulator transition (PIT). The finite-size errors are eliminated by using the non-commutative Kubo formula. The results reproduce all the key experimental characteristics of this transition in integer quantum Hall effect (IQHE) systems. In particular, the quantized Hall insulator (QHI) phase is detected and analyzed. The presently accepted characterization of the QHI phase in the quantum critical regime, based entirely on experimental data, is fully supported by our theoretical investigation.