The existence of a metal-insulator transition at zero magnetic field in two- dimensional electron systems has recently been confirmed in high mobility Si-MOSFETs. In this work, the temperature dependence of the resistivity of gated Si/SiGe/Si quantum well structures has revealed a similar metal- insulator transition as a function of carrier density at zero magnetic field. We also report evidence for a Coulomb gap in the temperature dependence of the resistivity of the dilute 2D hole gas confined in a SiGe quantum well. In addition, the resistivity in the insulating phase scales with a single parameter, and is sample independent. These results are consistent with the occurrence of a metal-insulator transition at zero magnetic field in SiGe square quantum wells driven by strong hole-hole interactions.
@article{arxiv.cond-mat/9708201,
title = {Scaling and the Metal-Insulator Transition in Si/SiGe Quantum Wells},
author = {J. Lam and M. D'Iorio and D. Brown and H. Lafontaine},
journal= {arXiv preprint arXiv:cond-mat/9708201},
year = {2009}
}