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Mesoscopic Behavior Near a Two-Dimensional Metal-Insulator Transition

Dragana Popović·S. Washburn
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Abstract

We study conductance fluctuations in a two-dimensional electron gas as a function of chemical potential (or gate voltage) from the strongly insulating to the metallic regime. Power spectra of the fluctuations decay with two distinct exponents (1/v_l and 1/v_h). For conductivity $σ\sim 0.1 e^{2}/h$, we find a third exponent (1/v_i) in the shortest samples, and non-monotonic dependence of v_i and v_l on σ. We study the dependence of v_i, v_l, v_h, and the variances of corresponding fluctuations on σ, sample size, and temperature. The anomalies near $σ\simeq 0.1 e^{2}/h$ indicate that the dielectric response and screening length are critically behaved, i.e. that Coulomb correlations dominate the physics.

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Dragana Popović, S. Washburn. 1997-03-21. Mesoscopic Behavior Near a Two-Dimensional Metal-Insulator Transition. https://doi.org/10.1103/physrevb.56.r10048

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