Measuring the local quantum capacitance of graphene using a strongly coupled graphene nanoribbon
arXiv:1505.07618 · doi:10.1103/PhysRevB.91.115441
Abstract
We present electrical transport measurements of a van-der-Waals heterostructure consisting of a graphene nanoribbon separated by a thin boron nitride layer from a micron-sized graphene sheet. The interplay between the two layers is discussed in terms of screening or, alternatively, quantum capacitance. The ribbon can be tuned into the transport gap by applying gate voltages. Multiple sites of localized charge leading to Coulomb blockade are observed in agreement with previous experiments. Due to the strong capacitive coupling between the ribbon and the graphene top layer sheet, the evolution of the Coulomb blockade peaks in gate voltages can be used to obtain the local density of states and therefore the quantum capacitance of the graphene top layer. Spatially varying density and doping are found which are attributed to a spatial variation of the dielectric due to fabrication imperfections.
References in corpus (18)
- Boron nitride substrates for high-quality graphene electronics
- Energy Band Gap Engineering of Graphene Nanoribbons
- Suspended Graphene: a bridge to the Dirac point
- Atomically thin p-n junctions with van der Waals heterointerfaces
- Vertical Field Effect Transistor based on Graphene-WS2 Heterostructures for flexible and transparent electronics
- Gate-induced insulating state in bilayer graphene devices
- Emergence of Superlattice Dirac Points in Graphene on Hexagonal Boron Nitride
- Atomically thin boron nitride: a tunnelling barrier for graphene devices
- Strong Coulomb drag and broken symmetry in double-layer graphene
- Quantum dot behavior in graphene nanoconstrictions
- Transport gap in side-gated graphene constrictions
- Gate defined zero- and one-dimensional confinement in bilayer graphene
- Coulomb Drag and Magnetotransport in Graphene Double Layers
- Reactive-Ion-Etched Graphene Nanoribbons on a Hexagonal Boron Nitride Substrate
- Characterizing wave functions in graphene nanodevices: electronic transport through ultrashort graphene constrictions on a boron nitride substrate
- Electronic triple-dot transport through a bilayer graphene island with ultrasmall constrictions
- Gate tunable quantum transport in double layer graphene
- Electron flow in split-gated bilayer graphene