Related papers: Remote capacitive sensing in two-dimension quantum…
Silicon spin qubits are promising candidates for realising large scale quantum processors, benefitting from a magnetically quiet host material and the prospects of leveraging the mature silicon device fabrication industry. We report the…
We report on the realization of a few-electron double quantum dot defined in a two-dimensional electron gas by means of surface gates on top of a GaAs/AlGaAs heterostructure. Two quantum point contacts (QPCs) are placed in the vicinity of…
The spin states of single electrons in gate-defined quantum dots satisfy crucial requirements for a practical quantum computer. These include extremely long coherence times, high-fidelity quantum operation, and the ability to shuttle…
The epitaxial growth of germanium on silicon leads to the self-assembly of SiGe nanocrystals via a process that allows the size, composition and position of the nanocrystals to be controlled. This level of control, combined with an inherent…
Universal quantum computation requires high fidelity single qubit rotations and controlled two qubit gates. Along with high fidelity single qubit gates, strong efforts have been made in developing robust two qubit logic gates in…
We report electronic transport on silicon double and triple dots created with the optimized number of two gates. Using silicon nitride spacers two dots in series are created below two top gates overlapping a silicon nanowire. Coupling…
We study a system of two symmetrical capacitively coupled quantum dots, each coupled to its own metallic lead, focusing on its evolution as a function of the gate voltage applied to each dot. Using the numerical renormalization group and…
Semiconductor nanowires can be utilized to create quantum dot qubits. The formation of quantum dots is typically achieved by means of bottom gates created by a lift-off process. As an alternative, we fabricated flat buried bottom gate…
We report a detailed study of low-temperature (mK) transport properties of a silicon double-dot system fabricated by phosphorous ion implantation. The device under study consists of two phosphorous nanoscale islands doped to above the…
We investigate the low temperature transport in 8 nm diameter Si junctionless nanowire field effect transistors fabricated by top down techniques with a wrap-around gate and two different activated doping densities. First we extract the…
We use the tip of an atomic force microscope (AFM) to charge floating metallic gates defined on the surface of a Si/SiGe heterostructure. The AFM tip serves as an ideal and movable cryogenic switch, allowing us to bias a floating gate to a…
We demonstrate single-charge occupation of ambipolar quantum dots in silicon via charge sensing. We have fabricated ambipolar quantum dot (QD) devices in a silicon metal-oxide-semiconductor heterostructure comprising a single-electron…
We report fast charge state readout of a double quantum dot in a CMOS split-gate silicon nanowire transistor via the large dispersive interaction with microwave photons in a lumped-element resonator formed by hybrid integration with a…
Systems of quantum dots (QD) connected to leads exhibit periodic conductance peaks as a function of gate voltage arising from the Coulomb blockade effect \cite{review1,review2,review3}. Much effort goes into minimizing the size of QDs and…
Quantum sensing techniques have been successful in pushing the sensitivity limits in numerous fields, and hold great promise for scanning probes that study nano-scale devices and novel materials. However, forming a nano-scale qubit that is…
Self-assembled semiconductor quantum dots show remarkable optical and spin coherence properties, which have lead to a concerted research effort examining their potential as a quantum bit for quantum information science1-6. Here, we present…
We report the experimental realization of double quantum dots in single-walled carbon nanotubes. The device consists of a nanotube with source and drain contact, and three additional top-gate electrodes in between. We show that, by…
A most fundamental and longstanding goal in spintronics is to electrically tune highly efficient spin injectors and detectors, preferably compatible with nanoscale electronics. Here, we demonstrate all these points using semiconductor…
We propose a new implementation of a universal set of one- and two-qubit gates for quantum computation using the spin states of coupled single-electron quantum dots. Desired operations are effected by the gating of the tunneling barrier…
Measurement of charge configurations in few-electron quantum dots is a vital technique for spin-based quantum information processing. While fast and high-fidelity measurement is possible by using proximal quantum dot charge sensors, their…