相关论文: Magnetic field induced charge redistribution in di…
We present transport measurements on quantum dots of sizes 45, 60 and 80 nm etched with an Ar/O2-plasma into a single graphene sheet, allowing a size comparison avoiding effects from different graphene flakes. The transport gaps and…
We report transport experiments on graphene quantum dots. We focus on excited state spectra in the near vicinity of the charge neutrality point and signatures of the electron-hole crossover as a function of a perpendicular magnetic field.…
Quantum dots induced by a strong magnetic field applied to a single layer of graphene in the perpendicular direction are investigated. The dot is defined by a model potential which consists of a well of depth $\Delta V$ relative to a flat…
We present transport measurements on a strongly coupled graphene quantum dot in a perpendicular magnetic field. The device consists of an etched single-layer graphene flake with two narrow constrictions separating a 140 nm diameter island…
We theoretically investigate the spectrum of a single electron double quantum dot, defined by top gates in a graphene with a substrate induced gap. We examine the effects of electric and magnetic fields on the spectrum of localized states,…
A tight-binding model with randomly fluctuating atomic positions is studied to discuss the effect of strong disorder in graphene. We employ a strong-disorder expansion for the transport quantities and find a diffusive behavior, where the…
Strain-inducing deformations in graphene alter charge distributions and provide a new method to design specific features in the band structure and transport properties. Novel approaches implement engineered substrates to induce specifically…
When charge transport occurs under conditions like topological protection or ballistic motion, the conductance of low-dimensional systems often exhibits quantized values in units of $e^{2}/h$, where $e$ and $h$ are the elementary charge and…
We investigate the addition spectrum of a graphene quantum dot in the vicinity of the electron-hole crossover as a function of perpendicular magnetic field. Coulomb blockade resonances of the 50 nm wide dot are visible at all gate voltages…
Graphene is a unique two-dimensional material with rich new physics and great promise for applications in electronic devices. Physical phenomena such as the half-integer quantum Hall effect and high carrier mobility are critically dependent…
The electronic states of an electrostatically confined cylindrical graphene quantum dot and the electric transport through this device are studied theoretically within the continuum Dirac-equation approximation and compared with numerical…
When an energy gap is induced in monolayer graphene the valley degeneracy is broken and the energy spectrum of a confined system such as a quantum dot, becomes rather complex exhibiting many irregular level crossings and small energy…
We study the effect of local modulation of charge density and carrier type in graphene field effect transistors using a double top gate geometry. The two top gates lead to the formation of multiple \emph{p-n} junctions. Electron transport…
We have measured the magneto-resistance of freely suspended high-mobility bilayer graphene. For magnetic fields $B>1$ T we observe the opening of a field induced gap at the charge neutrality point characterized by a diverging resistance.…
Distribution of charge induced by a gate voltage in a graphene strip is investigated. We calculate analytically the charge profile and demonstrate a strong(macroscopic) charge accumulation along the boundaries of a micrometers-wide strip.…
The effect of a magnetic field on the charged vacuum is investigated. The field dependence of the energy levels causes jumps in the total vacuum charge that occur whenever an energy level crosses the Fermi level and this leads to re-entrant…
We investigate the effects of wedge disclination on charge carriers in circular graphene quantum dots subjected to a magnetic flux. Using the asymptotic solutions of the energy spectrum for large arguments, we approximate the scattering…
We report on magneto-transport measurement in disordered graphene under pulsed magnetic field of up to 57T. For large electron or hole doping, the system displays the expected anomalous Integer Quantum Hall Effect (IQHE) specific to…
Using the tight-binding model, we investigate the influence of vacancy disorder on electrical transport in graphene Hall bars in the presence of quantizing magnetic fields. Disorder, induced by a random distribution of monovacancies, breaks…
We demonstrate electron redistribution caused by magnetic field on a single quantum dot measured by means of a quantum point contact as non-invasive detector. Our device which is fabricated by local anodic oxidation allows to control…