Edge channel confinement in a bilayer graphene $n$-$p$-$n$ quantum dot

TL;DR

This paper demonstrates the creation of a quantum dot in bilayer graphene using combined electrostatic and magnetic confinement, observing Coulomb blockade at around 2 Tesla, which is promising for quantum Hall interferometry.

Contribution

It introduces a novel method of defining a quantum dot in bilayer graphene by combining electrostatic and magnetic confinement techniques.

Findings

Coulomb blockade observed at B ≈ 2 T

Weak coupling of co-propagating modes enables tunnel barrier formation

Potential application in quantum Hall interferometry

Abstract

We combine electrostatic and magnetic confinement to define a quantum dot in bilayer graphene. The employed geometry couples $n$-doped reservoirs to a $p$-doped dot. At magnetic field values around $B = 2~$T, Coulomb blockade is observed. This demonstrates that the coupling of the co-propagating modes at the $p$-$n$ interface is weak enough to form a tunnel barrier, facilitating transport of single charge carriers onto the dot. This result may be of use for quantum Hall interferometry experiments.