Geometric engineering of viscous magnetotransport in a two-dimensional electron system

TL;DR

This paper experimentally investigates how device geometries in GaAs quantum wells influence viscous magnetotransport in two-dimensional electron systems, revealing tunable hydrodynamic effects at temperatures above 10 K.

Contribution

It introduces a method to manipulate hydrodynamic electron flow via device geometry modifications in GaAs quantum wells, providing a tunable platform for studying viscous transport.

Findings

Identified the impact of geometries on viscous flow parameters.

Determined scattering times for electron-electron and electron-phonon interactions.

Confirmed the system as a platform for hydrodynamic transport studies above 10 K.

Abstract

In this study, we present our experimental investigation on the magnetotransport properties of a two-dimensional electron system in GaAs quantum wells utilizing a variety of device geometries, including obstacles with thin barriers and periodic width variations. Our primary focus is to explore the impact of these geometries on the electron viscous flow parameters, enabling precise manipulation of hydrodynamic effects under controlled conditions. Through an analysis of the large negative magnetoresistivity and zero field resistivity, we deduce the scattering times for electron-electron and electron-phonon interactions, as well as the effective channel width. Our findings confirm that the system under investigation serves as a tunable experimental platform for investigating hydrodynamic transport regimes at temperatures above 10 K.