Inequivalence of the low-density insulating state and quantum Hall insulating states in a strongly correlated two-dimensional electron system
M. Yu. Melnikov, D. G. Smirnov, A. A. Shashkin, S. -H. Huang, C. W. Liu, S. V. Kravchenko
Published: 2025/4/3
Abstract
We find that the behaviors of the voltage-current characteristics as one enters the low-density insulating state and integer quantum Hall insulating states in the ultra-clean two-dimensional electron system in SiGe/Si/SiGe quantum wells are qualitatively different. The double-threshold voltage-current curves, representative of the electron solid formation at low densities, are not observed in the quantum Hall regime, which does not confirm the existence of a quasi-particle quantum Hall Wigner solid and indicates that quasi-particles near integer filling do not form an independent subsystem.