On the Phase Boundaries of the Integer Quantum Hall Effect. II

TL;DR

This paper clarifies that previous claims of observing phase transitions at higher integer quantum Hall states are incorrect, as the crossing points in resistivity are due to quantum corrections, not true phase transitions.

Contribution

It demonstrates that the crossing points previously identified as phase transitions are actually caused by quantum corrections, challenging earlier interpretations.

Findings

Crossing points are due to quantum corrections, not phase transitions.

Previous claims of transitions at $ u extgreater 2$ are unjustified.

Sign change in $d ho_{xx}/dT$ explains the crossing points.

Abstract

It is shown that the statements about the observation of the transitions between the insulating phase and the integer quantum Hall effect phases with the quantized Hall conductivity $\sigma_{xy}^{q}$ $\geq 3e^{2}/h$ made in a number of works are unjustified. In these works, the crossing points of the magnetic field dependences of the diagonal resistivity at different temperatures at $\omega_{c}\tau \approx 1$ have been misidentified as the critical points of the phase transitions. In fact, these crossing points are due to the sign change of the derivative $d\rho_{xx}/dT$ owing to the quantum corrections to the conductivity.