Related papers: Single Shot Charge Detection Using A Radio-Frequen…
We evaluate the charge noise acting on a GaAs/GaAlAs based semiconductor double quantum dot dipole-coupled to the voltage oscillations of a superconducting transmission line resonator. The in-phase ($I$) and the quadrature ($Q$) components…
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…
The radio frequency single electron transistor (rf-SET) possesses key requirements necessary for reading out a solid state quantum computer. This work explores the use of the rf-SET as a single-shot readout device in the presence of 1/f and…
Time-resolved electron dynamics in coupled quantum dots is directly observed by a pulsed-gate technique. While individual gate voltages are modulated with periodic pulse trains, average charge occupations are measured with a nearby quantum…
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…
Charge sensing is a sensitive technique for probing quantum devices, of particular importance for spin qubit readout. To achieve good readout sensitivities, the proximity of the charge sensor to the device to be measured is a necessity.…
We demonstrate dispersive readout of individual charge states in a gate-defined few-electron quantum dot in bilayer graphene. We employ a radio frequency reflectometry circuit, where an LC resonator with a resonance frequency close to 280…
The implementation of a quantum computer requires a qubit-specific measurement capability to read-out the final state of a quantum system. The model of spin dependent tunneling followed by charge readout has been highly successful in…
We present the experimental realization of a Quantum Dot (QD) operating as a high-frequency noise detector. Current fluctuations produced in a nearby Quantum Point Contact (QPC) ionize the QD and induce transport through excited states. The…
We performed measurements on a quantum dot and a capacitively coupled quantum point contact by using the sharp metallic tip of a low-temperature scanning force microscope as a scanned gate. The quantum point contact served as a detector for…
We report charge sensing measurements on a silicon quantum dot (QD) with a nearby silicon single electron transistor (SET) acting as an electrometer. The devices are electrostatically formed in bulk silicon using surface gates. We show that…
We use a double quantum dot as a frequency-tunable on-chip microwave detector to investigate the radiation from electron shot-noise in a near-by quantum point contact. The device is realized by monitoring the inelastic tunneling of…
Ultra-sensitive detectors and readout devices based on the radio frequency single electron transistor (rf-SET) combine near quantum-limited sensitivity with fast operation. Here we describe a twin rf-SET detector that uses two…
Compressibility measurements, sensitive to charge rearrangements, are performed on a quantum point contact (QPC). Screening due to mobile charges in the QPC is quantitatively measured, using a second point contact to detect the screened…
We demonstrate dispersive charge sensing of Si/SiGe single and double quantum dots (DQD) by coupling sub-micron floating gates to a radio frequency reflectometry (rf-reflectometry) circuit using the tip of an atomic force microscope (AFM).…
We address the ultimate charge detection scheme with a quantum point contact. It is shown that a superposed input state is necessary to exploit the full sensitivity of a quantum point contact detector. The coherence of the input state…
The generation, manipulation and detection of quantum bits (qubits) encoded on single photons is at the heart of quantum communication and optical quantum information processing. The combination of single-photon sources, passive optical…
We report charge sensing measurements of a silicon metal-oxide-semiconductor quantum dot using a single-electron transistor as a charge sensor with dynamic feedback control. Using digitallycontrolled feedback, the sensor exhibits sensitive…
We demonstrate a new method for measuring radio frequency (RF) electric fields based on quantum interference in an atom. Using a bright resonance prepared within an electromagnetically induced transparency window we are able to achieve a…
Quantum point contact or QPC -- a constriction in a semiconducting two-dimensional (2D) electron system with a quantized conductance -- has been found as the building block of novel spintronic, and topological electronic circuits. They can…