Temperature dependence of atomic vibrations in mono-layer graphene

We have measured the mean square amplitude of both in- and out-of-plane lattice vibrations for mono-layer graphene at temperatures ranging from ?100 K to 1300?K. The amplitude of lattice vibrations was calculated from data extracted from selected area electron diffraction patterns recorded across a known temperature range with over 80...

I-V characteristics of in-plane and out-of-plane strained edge-hydrogenated armchair graphene nanoribbons

The effects of tensile strain on the current-voltage (I-V) characteristics of hydrogenated-edge armchair graphene nanoribbons are investigated by using DFT theory. The strain is introduced in two different ways related to the two types of systems studied in this work: in-plane strained systems (A) and out-of-plane strained systems due to bending...

Confinement of charge carriers in bilayer graphene

In this thesis we investigate the fundamental properties of electronic transport in bilayer graphene. We do this by confining electrons to narrow constrictions and small islands. Our key result is the fabrication and measurement of nanoscale devices that permit confinement with electric fields in bilayer graphene for the first time on a...

Adiabatic quantum pumping via Dirac fermions

Josephson effects in carbon nanotube mechanical resonators and graphene

Formation and control of wrinkles in graphene by the wedging transfer method

We study the formation of wrinkles in graphene upon wet transfer onto a hydrophilic target substrate, whereby draining of water appears to play an important role. We are able to control the orientation of the wrinkles by tuning the surface morphology. Wrinkles are absent in flakes transferred to strongly hydrophobic substrates, a further...

Mechanical cleaning of graphene

Contamination of graphene due to residues from nanofabrication often introduces background doping and reduces electron mobility. For samples of high electronic quality, post-lithography cleaning treatments are therefore needed. We report that mechanical cleaning based on contact mode atomic force microscopy removes residues and significantly...

Quantum pumping in graphene with a perpendicular magnetic field

We consider quantum pumping of Dirac fermions in a monolayer of graphene in the presence of a perpendicular magnetic field in the central pumping region. The two external pump parameters are electrical voltages applied to the graphene sheet on either side of the pumping region. We analyze this pump within scattering matrix formalism and...

Optical constants of graphene measured by spectroscopic ellipsometry

A mechanically exfoliated graphene flake ( ? 150×380??m2) on a silicon wafer with 98 nm silicon dioxide on top was scanned with a spectroscopic ellipsometer with a focused spot ( ? 100×55??m2) at an angle of 55°. The spectroscopic ellipsometric data were analyzed with an optical model in which the optical constants were parameterized by B...