Relative importance of the electron interaction strength and disorder in the two-dimensional metallic state

Lewalle, A., Pepper, M., Ford, C.J.B., Hwang, E.H., Das Sarma, S., Paul, D.J. and Redmond, G. (2002) Relative importance of the electron interaction strength and disorder in the two-dimensional metallic state. Physical Review B, 66, 075324. (doi: 10.1103/PhysRevB.66.075324)

Abstract

The effect of substrate bias and surface gate voltage on the low-temperature resistivity of a Si-MOSFET is studied for electron concentrations where the resistivity increases with increasing temperature. This technique offers two degrees of freedom for controlling the electron concentration and the device mobility, thereby providing a means to evaluate the relative importance of electron-electron interactions and disorder in this so-called “metallic” regime. For temperatures well below the Fermi temperature, the data obey a scaling law where the disorder parameter (kFl), and not the concentration (and thus rs), appears explicitly. This suggests that interactions, although present, do not alter the Fermi-liquid properties of the system fundamentally. Furthermore, this experimental observation is reproduced in results of calculations based on temperature-dependent screening, in the context of Drude-Boltzmann theory.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Paul, Professor Douglas
• Authors: Lewalle, A., Pepper, M., Ford, C.J.B., Hwang, E.H., Das Sarma, S., Paul, D.J., and Redmond, G.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: Physical Review B
• Publisher: American Physical Society
• ISSN: 1098-0121
• ISSN (Online): 1550-235X