Related papers: Charge detection in a bilayer graphene quantum dot
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…
Using scanning tunneling microscopy, we have imaged local charge density fluctuations in monolayer graphene. By placing a small gold nanoparticle on the end of the STM tip, a charge sensor is created. By raster scanning the tip over the…
A highly sensitive charge detector is realized for a quantum dot in an InAs nanowire. We have developed a self-aligned etching process to fabricate in a single step a quantum point contact in a two-dimensional electron gas and a quantum dot…
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…
Stimulated by recent advances in isolating graphene, we discovered that quantum dot can be trapped in Z-shaped graphene nanoribbon junciton. The topological structure of the junction can confine electronic states completely. By varying…
Graphene nanoribbons display an imperfectly understood transport gap. We measure transport through nanoribbon devices of several lengths. In nanoribbons of length greater than or equal to 250 nm we observe transport through multiple quantum…
In this chapter, semi-analytical models for the calculation of the quantum capacitance of both monolayer and bilayer graphene and its nanoribbons, are presented. Since electron-hole puddles are experimental facts in all graphene samples,…
We present realistic simulations of quantum confinement effects in ballistic graphene quantum dots with linear dimensions of 10 to 40 nm. We determine wavefunctions and energy level statistics in the presence of disorder resulting from edge…
Bilayer graphene is a nanomaterial that allows for well-defined, separated quantum states to be defined by electrostatic gating and, therefore, provides an attractive platform to construct tunable quantum dots. When a magnetic field…
We report fast, simultaneous charge sensing and transport measurements of gate-defined carbon nanotube quantum dots. Aluminum radio frequency single electron transistors (rf-SETs) capacitively coupled to the nanotube dot provide…
The recent development of arrays of quantum dots in semiconductor nanostructures highlights the progress of quantum devices toward large scale. However, how to realize such arrays on a scalable platform such as silicon is still an open…
We have investigated electronic transport in graphene nanoribbon devices with additional bar-shaped extensions ("wings") at each side of the device. We find that the Coulomb-blockade dominated transport found in conventional ribbons is…
We study electron transport in nanostructures patterned in bilayer graphene patches grown epitaxially on SiC as a function of doping, magnetic field, and temperature. Away from charge neutrality transport is only weakly modulated by changes…
We investigate the application of nanoscale topgates on exfoliated bilayer graphene to define quantum dot devices. At temperatures below 500 mK the conductance underneath the grounded gates is suppressed, which we attribute to nearest…
The coherent dynamics of a quantum mechanical two-level system passing through an anti-crossing of two energy levels can give rise to Landau-Zener-St\"uckelberg-Majorana (LZSM) interference. LZSM interference spectroscopy has proven to be a…
We combine electrostatic and magnetic confinement to define a quantum dot in bilayer graphene. The employed geometry couples $n$-doped reservoirs to a $p$-doped dot. At magnetic field values around $B = 2~$T, Coulomb blockade is observed.…
We report on the observation of negative electronic compressibility in twisted bilayer graphene for Fermi energies close to insulating states. To observe this negative compressibility, we take advantage of naturally occurring twist angle…
We present electronic transport measurements through short and narrow (30x30 nm) single layer graphene constrictions on a hexagonal boron nitride substrate. While the general observation of Coulomb-blockade is compatible with earlier work,…
Spin qubits in germanium are a promising contender for scalable quantum computers. Reading out of the spin and charge configuration of quantum dots formed in Ge/Si core/shell nanowires is typically performed by measuring the current through…
Quantum confined devices that manipulate single electrons in graphene are emerging as attractive candidates for nanoelectronics applications. Previous experiments have employed etched graphene nanostructures, but edge and substrate disorder…