Transport measurements on an etched graphene nanoribbon are presented. It is shown that two distinct voltage scales can be experimentally extracted characterize the parameter region of suppressed conductance at low charge density in ribbon. One them related to charging energy localized states, other strength disorder potential. The lever arms gates vary by up 30% for different states which must therefore spread position along A single-electron transistor used prove addition individual...

We report electronic transport experiments on a graphene single electron transistor. The device consists of island connected to source and drain electrodes via two narrow constrictions. It is electrostatically tunable by three lateral gates an additional back gate. tunneling coupling strongly nonmonotonic function gate voltage indicating the presence localized states in barriers. investigate energy scales for gap, resonances constrictions, Coulomb blockade resonances. From diamond...

We report on Coulomb blockade and diamond measurements an etched, tunable single-layer graphene quantum dot. The device consisting of a island connected via two narrow constrictions is fully by three lateral gates. resonances are observed from measurements, charging energy ≈3.5meV extracted. For increasing temperatures, we detect peak broadening transmission increase the nanostructured barriers.

We present Kelvin probe force microscopy measurements of single- and few-layer graphene resting on SiO${}_{2}$ substrates. compare the layer thickness dependency measured surface potential with ab initio density functional theory calculations work function for substrate-doped graphene. The show that bilayer is mainly given by a variation Fermi energy respect to Dirac point as doping, electrostatic interlayer screening only becomes relevant thicker multilayer From Raman G-line shift...

Graphene is an attractive material for nanomechanical devices because it allows exceptional properties, such as high frequencies and quality factors, low mass. An outstanding challenge, however, has been to obtain large coupling between the motion external systems efficient readout manipulation. Here, we report on a novel approach, in which capacitively couple high-Q graphene mechanical resonator ($Q \sim 10^5$) superconducting microwave cavity. The initial exhibit single-photon of $\sim 10$...

We review transport experiments on graphene quantum dots and narrow constrictions. In a dot, electrons are confined in all lateral dimensions, offering the possibility for detailed investigation controlled manipulation of individual systems. The recently isolated two-dimensional carbon allotrope is an interesting host to study phenomena, due its novel electronic properties expected weak interaction electron spin with material. Graphene fabricated by etching mono-layer flakes into small...

We present measurements on side-gated graphene constrictions of different geometries. characterize the transport gap by its width in back-gate voltage and compare this to an analysis based Coulomb blockade localized states. study effect applied side-gate show that high voltages lift suppression conductance. Finally we magnetic field demonstrate presence edge states constriction.

Graphene, a single layer of carbon atoms forming perfectly stable and clean two-dimensional crystal with very few defects, has been proclaimed to be new revolutionary material for electronics. These hopes rest mainly on the unique band structure properties graphene. Although living essentially surface, electron mobilities in this do not suffer extensively from surface contaminations are surprisingly high even at room temperature. In comparison extremely quality semiconducting materials, such...

Abstract Mechanical resonators based on low-dimensional materials are promising for force and mass sensing experiments. The sensitivity in these ultra-light is often limited by the imprecision measurement of vibrations, fluctuations mechanical resonant frequency heating induced measurement. Here, we strongly couple multilayer graphene to superconducting cavities order achieve a displacement 1.3 fm Hz −1/2 . This coupling also allows us damp resonator an average phonon occupation 7.2. Our...

We investigate the addition spectrum of a graphene quantum-dot in vicinity electron-hole crossover as function perpendicular magnetic field. Coulomb-blockade resonances 50 nm wide dot are visible at all gate voltages across transport gap ranging from hole to electron transport. The field dependence more than states displays unique complex evolution diamagnetic low-field regime Landau with n=0 level situated center marking crossover. average peak spacing energy region around decreases...

We investigate ground and excited state transport through small (d≈70 nm) graphene quantum dots. The successive spin filling of orbital states is detected by measuring the difference between ground-state energies as a function magnetic field. For field in-plane dot Zeeman splitting measured. results are compatible with g factor 2, we detect spin-filling sequence for series which reasonable given strength exchange interaction effects expected comparing Coulomb energy kinetic charge carriers...

Ultralight mechanical resonators based on low-dimensional materials are well suited as exceptional transducers of minuscule forces or mass changes. However, the low dimensionality also provides a challenge to minimize resistive losses and heating. Here, we report novel approach that aims combine different 2D tackle this challenge. We fabricated heterostructure resonator consisting few layers niobium diselenide (NbSe$_2$) encapsulated by two graphene sheets. The hybrid membrane shows high...

We demonstrate that excited states in single-layer graphene quantum dots can be detected via direct transport experiments. Coulomb diamond measurements show distinct features of sequential tunneling through an state. Moreover, the onset inelastic cotunneling region could detected. For low magnetic fields, positions single-particle energy levels fluctuate on scale a flux penetrating dot area. higher transition to formation Landau is observed. Estimates based linear energy-momentum relation...

Abstract Despite recent progress in nano-optomechanics, active control of optical fields at the nanoscale has not been achieved with an on-chip nano-electromechanical system (NEMS) thus far. Here we present a new type hybrid system, consisting graphene NEMS suspended few tens nanometres above nitrogen-vacancy centres (NVCs), which are stable single-photon emitters embedded nanodiamonds. Electromechanical photons emitted by NVC is provided electrostatic tuning position, transduced to...

Probing techniques with spatial resolution have the potential to lead a better understanding of microscopic physical processes and novel routes for manipulating nanostructures. We present scanning-gate images graphene quantum dot which is coupled source drain via two constrictions. image locate conductance resonances in Coulomb-blockade regime as well localized states constrictions real space.

We report measurements on a graphene quantum dot with an integrated charge detector. The device consists of island (diameter ∼200 nm) connected to source and drain contacts via two narrow constrictions. From Coulomb diamond charging energy 4.3 meV is extracted. detector based 45 nm wide nanoribbon placed approximately 60 from the island. show that resonances in can be used detect individual events dot. induced potential change causes steplike current relative ranges 10% up 60% for detecting events.

We study a graphene double quantum dot in different coupling regimes. Despite the strong capacitive between dots, tunnel is below experimental resolution. observe additional structures inside finite-bias triangles, part of which can be attributed to electronic excited states, while others are probably due modulations transmission barriers connecting system source and drain leads.

We present Coulomb blockade measurements in a graphene double dot system. The coupling of the dots to leads and between can be tuned by in-plane gates. is non-monotonic function gate voltage. Using purely capacitive model, we extract all relevant energy scales

We report transport measurements on etched graphene nanoribbons. show that two distinct voltage (i.e. energy) scales can be experimentally extracted for characterizing the parameter regions of suppressed conductance at low charge density in The energy are related to charging localized states and strength disorder potential. discuss scaling behaviour these as a function minimum width w number different devices. Finally, we present model based Coulomb blockade, due quantum dots forming inside...

We present real-time detection measurements of electron tunneling in a graphene quantum dot. By counting single-electron charging events on the dot, process constriction and role localized states are studied detail. In regime low charge detector bias we see only single time-dependent rate which can be modeled using Fermi-broadened energy distribution carriers lead. find nonmonotonic gate dependence coupling attributed to formation constriction. Increasing above ${V}_{b}=2$ mV results an...