Potential of Graphene/AlGaN/GaN heterostructures to study the drag and two-stream instability effects

TL;DR

This paper explores the potential of graphene/AlGaN/GaN heterostructures as a platform for studying drag and two-stream instability effects, demonstrating quantum oscillations and temperature-dependent behavior of drag currents.

Contribution

It introduces a novel heterostructure setup with transferred graphene on AlGaN/GaN, enabling new experimental investigation of drag phenomena and instabilities.

Findings

Quantum oscillations of drag current at low temperatures

Increase of drag current magnitude with temperature

Potential for studying instabilities with thinner barriers

Abstract

Graphene/AlGaN/GaN heterostructures are proposed to investigate the drag and two-stream instability effects. In this study, graphene grown by chemical vapor deposition was transferred from copper onto the top of the standard AlGaN/GaN wafer, forming a heterostructure with two conducting layers separated by an AlGaN barrier layer. Contacts fabricated to the two-dimensional electron gas and graphene allowed us to study the drag current induced in graphene by passing the drive current through the two-dimensional electron gas. At low temperatures, the graphene drag current exhibited quantum oscillations as a function of the drive voltage. As temperature increases, quantum oscillations disappear, and the magnitude of the drag current increases. Graphene/AlGaN/GaN heterostructures are a promising platform for studying drag and two-stream instability effects, especially if the AlGaN barrier layer thickness can be reduced to a few nanometers.