| Autor: |
D'iorio, M., Brown, D., Lam, J., Stewart, D., Deblois, S., Lafontaine, H. |
| Zdroj: |
Superlattices and Microstructures; January 1998, Vol. 23 Issue: 1 p55-59, 5p |
| Abstrakt: |
The temperature dependence of the resistivity of gated Si-SiGe quantum-well structures has revealed a metal–insulator transition as a function of carrier density at zero magnetic field. Although early scaling theories have argued against the existence of a metal–insulator transition at zero temperature in infinite two-dimensional systems, it is now clear experimentally that such a transition can occur in systems with short-range scatterers. We have studied the magneto-transport properties of holes confined in strained p-type Si-Si0.87Ge0.13-Si quantum wells grown by ultra-high-vacuum chemical-vapor deposition. In the temperature range 25 mK–4.2 K, there is a transition from an insulating phase at low carrier densities to a metallic phase at high carrier densities with a transition boundary near 3.3×1011cm−2. Evidence for a Coulomb gap is presented in the insulating phase. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
Full Text from ScienceDirect