Thermodynamic magnetization of a strongly interacting two-dimensional system

TL;DR

This study measures the thermodynamic magnetization of a high-mobility 2D electron gas, revealing a divergence in susceptibility inconsistent with Fermi-liquid theory, indicating strong interactions.

Contribution

It provides experimental evidence of non-Fermi-liquid behavior in 2D electron systems through thermodynamic magnetization measurements.

Findings

Magnetization is a strongly sub-linear function of magnetic field.

Susceptibility diverges as 1/T^{lpha} with lpha=2.2-2.6.

Results challenge the Fermi-liquid description of 2D electron gases.

Abstract

We report thermodynamic magnetization measurements of a 2-dimensional electron gas for several high mobility Si-MOSFETs. The low-temperature magnetization is shown to be strongly sub-linear function of the magnetic field. The susceptibility determined from the zero-field slope diverges as 1/T^{\alpha}, with \alpha=2.2-2.6 even at high electron densities, in apparent contradiction with the Fermi-liquid picture.