Abstract
We report the observation of a reentrant insulator-metal-insulator transition at in a two-dimensional (2D) hole gas in GaAs at temperatures down to 30 mK. At the lowest carrier densities the holes are strongly localized. As the carrier density is increased a metallic phase forms, with a clear transition at . Further increasing the density weakens the metallic behavior and eventually leads to the formation of a second insulating state for . In the limit of high carrier densities, where is large and is small, we thus recover the results of previous work on weakly interacting systems showing the absence of a 2D metallic state.
- Received 29 July 1998
DOI:https://doi.org/10.1103/PhysRevLett.82.1542
©1999 American Physical Society