Diffusion and ballistic contributions of the interaction correction to the conductivity of a two-dimensional electron gas

TL;DR

This study experimentally investigates the quantum interaction correction to conductivity in a two-dimensional electron gas, distinguishing between ballistic and diffusion contributions and measuring Fermi-liquid parameters across various temperature regimes.

Contribution

It provides the first detailed experimental separation of ballistic and diffusion parts of the interaction correction in 2D electron gases and measures related Fermi-liquid parameters.

Findings

Ballistic correction mainly renormalizes electron mobility.

Diffusion correction affects diagonal conductivity components.

Fermi-liquid parameters agree with theoretical predictions.

Abstract

The results of an experimental study of interaction quantum correction to the conductivity of two-dimensional electron gas in A$_3$B$_5$ semiconductor quantum well heterostructures are presented for a wide range of $T\tau$-parameter ($T\tau\simeq 0.03-0.8$), where $\tau$ is the transport relaxation time. A comprehensive analysis of the magnetic field and temperature dependences of the resistivity and the conductivity tensor components allows us to separate the ballistic and diffusion parts of the correction. It is shown that the ballistic part renormalizes in the main the electron mobility, whereas the diffusion part contributes to the diagonal and does not to the off-diagonal component of the conductivity tensor. We have experimentally found the values of the Fermi-liquid parameters describing the electron-electron contribution to the transport coefficients, which are found in a good agreement with the theoretical results.