# Observation of Coulomb blockade in nanostructured epitaxial bilayer graphene on SiC

## TL;DR

This study demonstrates Coulomb blockade phenomena in nanostructured epitaxial bilayer graphene on SiC, revealing how electron transport is affected by doping, magnetic field, and temperature, with implications for quantum electronic applications.

## Contribution

It provides the first detailed observation of Coulomb blockade in epitaxial bilayer graphene nanostructures, highlighting the effects of magnetic field and charge neutrality on electron transport.

## Key findings

- Coulomb blockade observed near charge neutrality
- Magnetic field causes fluctuations in Coulomb blockade resonances
- Conductance suppression at charge neutrality indicates broken symmetry

## Abstract

We study electron transport in nanostructures patterned in bilayer graphene patches grown epitaxially on SiC as a function of doping, magnetic field, and temperature. Away from charge neutrality transport is only weakly modulated by changes in carrier concentration induced by a local side-gate. At low n-type doping close to charge neutrality, electron transport resembles that in exfoliated graphene nanoribbons and is well described by tunnelling of single electrons through a network of Coulomb-blockaded islands. Under the influence of an external magnetic field, Coulomb blockade resonances fluctuate around an average energy and the gap shrinks as a function of magnetic field. At charge neutrality, however, conduction is less insensitive to external magnetic fields. In this regime we also observe a stronger suppression of the conductance below $T^*$, which we interpret as a sign of broken interlayer symmetry or strong fluctuations in the edge/potential disorder.