We report on a zero magnetic field transport study of a two-dimensional, variable-density, hole system in GaAs. As the density is varied we observe, for the first time in GaAs-based materials, a crossover from an insulating behavior at low-density, to a metallic-like behavior at high-density, where the metallic behavior is characterized by a large drop in the resistivity as the temperature is lowered. These results are in agreement with recent experiments on Si-based two-dimensional systems by Kravchenko et al. and others. We show that, in the metallic region, the resistivity is dominated by an exponential temperature-dependence with a characteristic temperature which is proportional to the hole density, and appear to reach a constant value at lower temperatures.
@article{arxiv.cond-mat/9709184,
title = {The Metallic-Like Conductivity of a Two-Dimensional Hole System},
author = {Y. Hanein and U. Meirav and D. Shahar and C. C. Li and D. C. Tsui and Hadas Shtrikman},
journal= {arXiv preprint arXiv:cond-mat/9709184},
year = {2016}
}