Physics of the Insulating Phase in the Dilute Two-Dimensional Electron Gas

TL;DR

This paper explores advanced techniques to investigate the insulating phase of dilute two-dimensional electron gases, revealing critical fluctuations near the metal-insulator transition through proposed experimental methods.

Contribution

It introduces novel experimental approaches using radio-frequency single-electron transistors and optically-pumped NMR to probe electron lattice dynamics and spin structure.

Findings

Electron effective mass is strongly enhanced near the transition.

Spin susceptibility increases due to critical fluctuations.

Proposed methods can detect sliding electron lattice signals.

Abstract

We propose to use the radio-frequency single-electron transistor as an extremely sensitive probe to detect the time-periodic ac signal generated by sliding electron lattice in the insulating state of the dilute two-dimensional electron gas. We also propose to use the optically-pumped NMR technique to probe the electron spin structure of the insulating state. We show that the electron effective mass and spin susceptibility are strongly enhanced by critical fluctuations of electron lattice in the vicinity of the metal-insulator transition, as observed in experiment.