Effect of Local Magnetic Moments on the Metallic Behavior in Two Dimensions

TL;DR

This study investigates how local magnetic moments, introduced by disorder, affect the metallic behavior of a two-dimensional electron system in silicon, showing that even minimal magnetic scattering suppresses metallicity at low temperatures.

Contribution

It demonstrates that local magnetic moments can suppress metallic behavior in two-dimensional electron systems, highlighting the impact of magnetic scattering on conductivity.

Findings

Local magnetic moments suppress metallic behavior at low temperatures.

Even small amounts of magnetic scattering can eliminate metallicity.

The number of local moments was controlled via substrate bias.

Abstract

The temperature dependence of conductivity $\sigma (T)$ in the metallic phase of a two-dimensional electron system in silicon has been studied for different concentrations of local magnetic moments. The local moments have been induced by disorder, and their number was varied using substrate bias. The data suggest that in the limit of $T\to 0$ the metallic behavior, as characterized by $d\sigma/dT < 0$, is suppressed by an arbitrarily small amount of scattering by local magnetic moments.