Related papers: Crossover from Coulomb blockade to quantum Hall ef…
Graphene nanoribbons and constrictions are envisaged as fundamental components of future carbon-based nanoelectronic and spintronic devices. At nanoscale, electronic effects in these devices depend heavily on the dimensions of the active…
When a graphene layer is stressed, the strain alters the phase an electron accumulates hopping between sites in a way that can be modeled as arising from a pseudo-magnetic vector potential. We examine the case of an oscillating graphene…
We investigate electronic transport in n-i-n GaN nanowires with and without AlN double barriers. The nanowires are grown by catalyst-free, plasma-assisted molecular beam epitaxy enabling abrupt GaN/AlN interfaces as well as longitudinal…
We report on quantum transport measurements on etched graphene nanoribbons encapsulated in hexagonal boron nitride (hBN). At zero magnetic field our devices behave qualitatively very similar to what has been reported for graphene…
We describe charging a quantum dot induced electrostatically within a semiconducting graphene nanoribbon by electrons or holes. The applied model is based on a tight-binding approach with the electron-electron interaction introduced by a…
Electrical contacts between nano-engineered systems are expected to constitute the basic building blocks of future nano-scale electronics. However, the accurate characterization and understanding of electrical contacts at the nano-scale is…
Confinement of electrons in graphene to make devices has proven to be a challenging task. Electrostatic methods fail because of Klein tunneling, while etching into nanoribbons requires extreme control of edge terminations, and bottom-up…
We perform transport measurements in high quality bilayer graphene pnp junctions with suspended top gates. At a magnetic field B=0, we demonstrate band gap opening by an applied perpendicular electric field, with an On/Off ratio up to…
Considerable efforts have been made to trap massless Dirac fermions in graphene monolayer, but only quasi-bound states are realized in continuous graphene sheets up to now. Here, we demonstrate the realization of bound states in nanoscale…
We investigate the problem of dynamical gap generation in suspended graphene by long-range Coulomb interactions at strong coupling with Dyson-Schwinger equations. Including renormalization effects on the Fermi velocity we obtain a critical…
The success of all-graphene electronics is severely hindered by the challenging realization and subsequent integration of semiconducting channels and metallic contacts. Here, we comprehensively investigate the electronic transport across…
We study the effects of the interaction between electrons and holes on the conductance G of quasi-one-dimensional graphene systems. We first consider as a benchmark the limit in which all interactions are negligible, recovering the…
In quantum Hall systems with two narrow constrictions, tunneling between opposite edges can give rise to quantum interference and Aharonov-Bohm-like oscillations of the conductance. When there is an integer quantized Hall state within the…
We analyze charging effects in graphene quantum dots. Using a simple model, we show that, when the Fermi level is far from the neutrality point, charging effects lead to a shift in the electrostatic potential and the dot shows standard…
We investigate magneto-transport through graphene nano-ribbons as a function of gate and bias voltage, and temperature. We find that a magnetic field systematically leads to an increase of the conductance on a scale of a few tesla. This…
We present measurements of tunneling magneto-resistance (TMR) in single-wall carbon nanotubes attached to ferromagnetic contacts in the Coulomb blockade regime. Strong variations of the TMR with gate voltage over a range of four conductance…
We investigate electronic transport in lithographically patterned graphene ribbon structures where the lateral confinement of charge carriers creates an energy gap near the charge neutrality point. Individual graphene layers are contacted…
We have fabricated graphene nano-ribbon field-effect transistor devices and investigated their electrical properties as a function of ribbon width. Our experiments show that the resistivity of a ribbon increases as its width decreases,…
The electrostatic confinement of massless charge carriers is hampered by Klein tunneling. Circumventing this problem in graphene mainly relies on carving out nanostructures or applying electric displacement fields to open a band gap in…
A graphene nano-ribbon with armchair edges is known to have no edge state. However, if the nano-ribbon is in the quantum spin Hall (QSH) state, then there must be helical edge states. By folding a graphene ribbon to a ring and threading it…