Suppression of metallic behavior in two dimensions by spin flip scattering

TL;DR

This study investigates how disorder, especially spin flip scattering from local magnetic moments, suppresses metallic behavior in a two-dimensional silicon electron system at low temperatures.

Contribution

It reveals that even minimal spin flip scattering from magnetic moments can eliminate metallic behavior in 2D electron systems, highlighting the role of magnetic disorder.

Findings

Spin flip scattering strongly affects conductivity temperature dependence.

Metallic behavior is suppressed by small amounts of magnetic disorder.

Disorder-induced magnetic moments influence low-temperature electron transport.

Abstract

We study the effect of the disorder on the metallic behavior of a two-dimensional electron system in silicon. The temperature dependence of conductivity $\sigma (T)$ was measured for different values of substrate bias, which changes both potential scattering and the concentration of disorder-induced local magnetic moments. We find that the latter has a much more profound effect on $d\sigma/dT$. In fact, 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 spin flip scattering by local magnetic moments.