Conductance Fluctuations Near the Two-Dimensional Metal-Insulator Transition

Abstract

Measurements of conductance $G$ on short, wide, high-mobility Si-MOSFETs reveal both a two-dimensional metal-insulator transition (MIT) at moderate temperatures (1 $<T<$ 4~K) and mesoscopic fluctuations of the conductance at low temperatures ($T<$ 1~K). Both were studied as a function of chemical potential (carrier concentration $n_s$) controlled by gate voltage ($V_g$) and magnetic field $B$ near the MIT. Fourier analysis of the low temperature fluctuations reveals several fluctuation scales in $V_g$ that vary non-monotonically near the MIT. At higher temperatures, $G(V_g,B)$ is similar to large FETs and exhibits a MIT. All of the observations support the suggestion that the MIT is driven by Coulomb interactions among the carriers.

4 pages, LaTeX, physica.sty (slightly modified prabib.sty), Submitted to the 1997 Conference on Electronic Properties of Two-Dimensional Systems

References in corpus (2)

• Scaling theory of two-dimensional metal-insulator transitions
• Instability of the Two-Dimensional Metallic Phase to Parallel Magnetic Field