Abstract
We have studied the temperature dependence of resistivity, ρ, for a two-dimensional electron system in silicon at low electron densities ∼ , near the metal-insulator transition. The resistivity was empirically found to scale with a single parameter , which approaches zero at some critical electron density and increases as a power ∝‖- with β=1.6±0.1 both in metallic (>) and insulating (<) regions. This dependence was found to be sample independent. We have also studied the diagonal resistivity at Landau-level filling factor ν=3/2, where the system is known to be in a true metallic state at high magnetic field and in an insulating state at low magnetic field. The temperature dependencies of resistivity at B=0 and ν=3/2 were found to be identical. These behaviors suggest a true metal-insulator transition in the two-dimensional electron system in silicon at B=0, in contrast with the well-known scaling theory.
- Received 2 November 1994
DOI:https://doi.org/10.1103/PhysRevB.51.7038
©1995 American Physical Society