Conductance fluctuations near Anderson transition

TL;DR

This study measures conductance fluctuations in doped silicon near the metal-insulator transition, finding that noise does not diverge at the transition and exhibits a maximum before sharply decreasing in the insulating state.

Contribution

It provides experimental insights into conductance noise behavior near the Anderson transition in doped silicon, highlighting the non-divergent nature of fluctuations.

Findings

Noise does not diverge as the transition is approached from the metallic side.

Maximum noise occurs around k_{F}l \\approx 1.5.

Noise drops sharply approaching the insulating state.

Abstract

In this paper we report measurements of conductance fluctuations in single crystal samples of Si doped with P and B close to the critical composition of the metal insulator transition (n_c \approx 4 x 10^18 /cc). The measurements show that the noise, which arises from bulk sources, does not diverge as the Ioffe-Regal limit (k_{F}l -> 1) is approached from the metallic side. At room temperatures, the magnitude of the noise shows a shallow maximum around k_{F}l \approx 1.5 and drops sharply as the insulating state is approached.