Spin-Droplet State of an Interacting 2D Electron System

TL;DR

This study investigates the magnetic properties of 2D electrons in high mobility Si MOSFETs, revealing large-spin droplets in the insulating phase that diminish with increased density and temperature, impacting the understanding of electron interactions.

Contribution

It provides experimental evidence for large-spin droplet formation in 2D electron systems and their evolution across insulating and metallic phases.

Findings

Evidence of easily polarizable electron states across a wide density range.

Large-spin droplets form in the insulating phase and melt in the metallic phase.

Droplets persist at high densities despite melting with increased temperature.

Abstract

We report thermodynamic magnetization measurements of two-dimensional electrons in several high mobility Si metal-oxide-semiconductor field-effect transistors. We provide evidence for an easily polarizable electron state in a wide density range from insulating to deep into the metallic phase. The temperature and magnetic field dependence of the magnetization is consistent with the formation of large-spin droplets in the insulating phase. These droplets melt in the metallic phase with increasing density and temperature, although they survive up to large densities.