Related papers: Single-electron double quantum dots in bilayer gra…
A gate-defined quantum dot in bilayer graphene is utilized as a sensitive electrometer for probing the charge density of its environment. Under the influence of a perpendicular magnetic field, the charge carrier density of the channel…
We present real-time detection measurements of electron tunneling in a graphene quantum dot. By counting single electron charging events on the dot, the tunneling process in a graphene constriction and the role of localized states are…
We have developed an etching process to fabricate a quantum dot and a nearby single electron transistor as a charge detector in a single layer graphene. The high charge sensitivity of the detector is used to probe Coulomb diamonds as well…
We investigate the characteristics of purely electrostatic interactions with external gates in constructing full single qubit manipulations. The quantum bit is naturally encoded in the spatial wave function of the electron system.…
Single-electron occupation is an essential component to measurement and manipulation of spin in quantum dots, capabilities that are important for quantum information processing. Si/SiGe is of interest for semiconductor spin qubits, but…
We report the fabrication and measurement of one-electron single and double quantum dots with fast tunnel rates in a Si/SiGe heterostructure. Achieving fast tunnel rates in few-electron dots can be challenging, in part due to the large…
We present an electronic transport experiment in graphene where both classical and quantum mechanical charge detector back-action on a quantum dot are investigated. The device consists of two stacked graphene quantum dots separated by a…
The precise control of a bilayer system consisting of two adjacent two-dimensional electron gases (2DEG) is demonstrated by using a novel planar back-gate approach based on ion implantation. This technique overcomes some common problems of…
In situ tunable radio-frequency charge detection is used for the determination of the tunneling rates into and out of a graphene single quantum dot connected to only one lead. An analytical model for calculating these rates in the…
Electron spins in semiconductors are promising qubits because their long coherence times enable nearly 10^9 coherent quantum gate operations. However, developing a scalable high-fidelity two-qubit gate remains challenging. Here, we…
A lateral quantum dot design for coherent electrical manipulation of a two-level spin-charge system is presented. Two micron-size permanent magnets integrated to high-frequency electrodes produce a static slanting magnetic field suitable…
We experimentally investigate electrical transport properties of graphene, which is a two dimensional (2D) conductor with relativistic energy dispersion relation. By investigating single- and bi-layer graphene devices with different aspect…
We demonstrate a 12 quantum dot device fabricated on an undoped Si/SiGe heterostructure as a proof-of-concept for a scalable, linear gate architecture for semiconductor quantum dots. The device consists of 9 quantum dots in a linear array…
The transport spectrum of a strongly tunnel-coupled one-electron double quantum dot electrostatically defined in a GaAs/AlGaAs heterostructure is studied. At finite source-drain-voltage we demonstrate the unambiguous identification of the…
Electrostatically confined quantum dots in bilayer graphene have shown potential as building blocks for quantum technologies. To operate the dots, e.g., as qubits, a precise understanding and control of the confined states and their…
We report on low-temperature electronic transport measurements of a silicon metal-oxide-semiconductor quantum dot, with independent gate control of electron densities in the leads and the quantum dot island. This architecture allows the dot…
The edge states of the quantum Hall and fractional quantum Hall effect of a two-dimensional electron gas provide key access to the excitations of the bulk. Here we demonstrate controlled transmission of edge states in bilayer graphene.…
By taking into account the full four band energy spectrum, we calculate the transmission probability and conductance of electrons across symmetric and asymmetric double potential barrier with a confined interlayer potential difference in…
We report on measurements of quantized conductance in gate-defined quantum point contacts in bilayer graphene that allow the observation of subband splittings due to spin-orbit coupling. The size of this splitting can be tuned from 40 to 80…
We investigate the transport properties of double-gated bilayer graphene nanoribbons at room temperature. The devices were fabricated using conventional CMOS-compatible processes. By analyzing the dependence of the resistance at the charge…