# Electrical Transport in High Quality Graphene pnp Junctions

## TL;DR

This paper reports on the fabrication and analysis of high-quality graphene pnp junctions with tunable doping, revealing quantum interference effects and quantum Hall phenomena in the devices.

## Contribution

It introduces a contactless, suspended top gate technique for high-quality graphene pnp junctions and studies their transport properties under various conditions.

## Key findings

- Observation of Fabry-Perot interference oscillations in resistance
- Detection of well-defined quantum Hall plateaus
- Agreement of quantum Hall data with theoretical models

## Abstract

We fabricate and investigate high quality graphene devices with contactless, suspended top gates, and demonstrate formation of graphene pnp junctions with tunable polarity and doping levels. The device resistance displays distinct oscillations in the npn regime, arising from the Fabry-Perot interference of holes between the two pn interfaces. At high magnetic fields, we observe well-defined quantum Hall plateaus, which can be satisfactorily fit to theoretical calculations based on the aspect ratio of the device.

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Source: https://tomesphere.com/paper/0907.3366