Improvement of the transport properties of a high-mobility electron system by intentional parallel conductance

TL;DR

This paper introduces a gating method to distinguish and control parallel conductance in a high-mobility 2D electron system, improving the understanding of its transport properties and the effects of nearby charge carriers.

Contribution

A novel gating scheme is developed to isolate and study the impact of parallel conductance on the transport properties of 2D electron systems.

Findings

Parallel conductance can be effectively separated from the main 2D system.

Adjusting the electron density in the parallel layer influences the screening of impurity potential.

Screening by the parallel layer enhances the stability of fractional quantum Hall states.

Abstract

We present a gating scheme to separate even strong parallel conductance from the magneto-transport signatures and properties of a two-dimensional electron system. By varying the electron density in the parallel conducting layer, we can study the impact of mobile charge carriers in the vicinity of the dopant layer on the properties of the two-dimensional electron system. It is found that the parallel conducting layer is indeed capable to screen the remote ionized impurity potential fluctuations responsible for the fragility of fractional quantum Hall states.