Magnetoconductivity of Insulating Silicon Inversion Layers

TL;DR

This paper investigates how the in-plane magnetoconductivity of dilute electrons in silicon MOSFETs scales with magnetic field and temperature, revealing a new energy scale and phase distinctions near the metal-insulator transition.

Contribution

It identifies a new energy scale in the magnetoconductivity of silicon inversion layers and explores its relation to the metal-insulator transition and phase behavior.

Findings

Magnetoconductivity scales with B/T at low densities.

A new energy scale k_B Δ emerges at higher densities.

Scaling breaks down near the critical density n_c.

Abstract

The normalized in-plane magnetoconductivity of the dilute strongly interacting system of electrons in silicon MOSFET's scales with $B/T$ for low densities in the insulating phase. Pronounced deviations occur at higher metallic-like densities, where a new energy scale $k_B \Delta$ emerges which is not associated with either magnetic field or thermal effects. $B/T$ scaling of the magnetoconductivity breaks down at the density $n_0$ where the energy scale $k_B \Delta$ vanishes, near or at the critical density $n_c$ for the apparent metal-insulator transition. The different behavior of the magnetoconductivity at low and high densities suggests the existence of two distinct phases.