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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…
Band gap engineering in graphene may open the routes towards transistor devices in which electric current can be switched off and on at will. One may, however, ask if a semiconducting band gap alone is sufficient to quench the current in…
To study the influence of microwave irradiation on two-dimensional electrons, we apply a method based on capacitance measurements in GaAs quantum well samples where the gate covers a central part of the layer. We find that the capacitance…
We found an intrinsic redistribution of charge arises between epitaxial graphene, which has intrinsically n-type doping, and an undoped substrate. In particular, we studied in detail epitaxial graphene layers thermally elaborated on…
Quantum Hall effect (QHE) devices based on epitaxial graphene films grown on SiC were fabricated and studied for development of the QHE resistance standard. The graphene-metal contacting area in the Hall devices has been improved and…
We present detailed simulations addressing recent electronic interference experiments, where a metallic gate is used to locally modify the Fermi wave-length of the charge carriers. Our numerical calculations are based on a solution of the…
This study simulated negative-capacitance double gate FinFETs with channel lengths ranging from 25nm to 100nm using TCAD. The results show that negative capacitance significantly reduces subthreshold swing as well as drain induced barrier…
The gate-voltage-induced suppression of critical currents in metallic superconductors observed recently [De Simoni et al., Nat. Nanotechnol. 13, 802 (2018)] has raised crucial questions regarding the nature and mechanism of the electric…
Devices made from two dimensional materials such as graphene and transition metal dichalcogenides exhibit remarkable electronic properties of interest to many subdisciplines of nanoscience. Owing to their 2D nature, their quality is highly…
We have developed a process to fabricate suspended graphene devices with local bottom gates, and tested it by realizing electrostatically controlled pn junctions on a suspended graphene mono-layer nearly 2 micrometers long. Measurements as…
We present numerical simulations of the capacitive coupling between graphene nanoribbons of various widths and gate electrodes in different configurations. We compare the influence of lateral metallic or graphene side gate structures on the…
We report the direct observation of polarization resolved electronic Raman scattering in a gated monolayer graphene device. The evolution of the electronic Raman scattering spectra with gate voltage and its polarization dependence are in…
In recent years, graphene Field-Effect-Transistors (GFETs) have demonstrated an outstanding potential for Terahertz (THz) photodetection due to their fast response and high-sensitivity. Such features are essential to enable emerging THz…
Large-angle twisted bilayer graphene (tBLG) is known to be electronically decoupled due to the spatial separation of the Dirac cones corresponding to individual graphene layers in the reciprocal space. The close spacing between the layers…
Large capacitance enhancement is useful for increasing the gate capacitance of field-effect transistors (FETs) to produce low-energy-consuming devices with improved gate controllability. We report strong capacitance enhancement effects in a…
We explore the use of applied electrical potentials to induce band flattening in graphene for bands near zero energy. We consider various families of doubly periodic potentials and simulate their effect on the electronic band structure…
Coulomb blockade is observed in a graphene nanoribbon device with a top gate. When two pn junctions are formed via the back gate and the local top gate, electrons are confined between the pn junctions which act as the barriers. When no pn…
There is an increasing amount of literature concerning electronic properties of graphene close to the neutrality point. Many experiments continue using the two-probe geometry or invasive contacts or do not control samples' macroscopic…
By means of an envelope function analysis, we perform a numerical investigation of the conductance behavior of a graphene structure consisting of two regions (dots) connected to the entrance and exit leads through constrictions and…
The classical picture of the force on a capacitor assumes a large density of electronic states, such that the electrochemical potential of charges added to the capacitor is given by the external electrostatic potential and the capacitance…