Disorder and temperature renormalization of interaction contribution to the conductivity in two-dimensional In$_{x}$Ga$_{1-x}$As electron systems

TL;DR

This study investigates how disorder and temperature affect electron-electron interactions in two-dimensional InGaAs systems, revealing that renormalization group theory aligns with experiments at high conductivities but fails at lower conductivities, especially regarding magnetic field effects.

Contribution

It provides experimental validation and limitations of one-loop RG theory in describing interaction effects in 2D electron systems across different conductivity regimes.

Findings

RG theory matches high conductivity data (σ > 15 G_0)

Discrepancies at low conductivity with theory predictions

Experimental interaction contribution is insensitive to magnetic field

Abstract

We study the electron-electron interaction contribution to the conductivity of two-dimensional In$_{0.2}$Ga$_{0.8}$As electron systems in the diffusion regime over the wide conductivity range, $\sigma\simeq(1-150) G_0$, where $G_0=e^2/(2\pi^2\hbar)$. We show that the data are well described within the framework of the one-loop approximation of the renormalization group (RG) theory when the conductivity is relatively high, $\sigma \gtrsim 15 G_0$. At lower conductivity, the experimental results are found to be in drastic disagreement with the predictions of this theory. The theory predicts much stronger renormalization of the Landau's Fermi liquid amplitude, which controls the interaction in the triplet channel, than that observed experimentally. A further contradiction is that the experimental value of the interaction contribution does not practically depend on the magnetic field, whereas the RG theory forecasts its strong decrease due to decreasing diagonal component of the conductivity tensor in the growing magnetic field.