Related papers: Single Shot Charge Detection Using A Radio-Frequen…
We present finite bias measurements on a quantum dot coupled capacitively to a quantum point contact used as a charge detector. The transconductance signal measured in the quantum point contact at finite dot bias shows structure which…
We use time-resolved charge detection techniques to investigate single-electron tunneling in semiconductor quantum dots. The ability to detect individual charges in real-time makes it possible to count electrons one-by-one as they pass…
Spin qubits in silicon quantum dots offer a promising platform for a quantum computer as they have a long coherence time and scalability. The charge sensing technique plays an essential role in reading out the spin qubit as well as tuning…
Owing to their strong dipole moment and long coherence times, superconducting qubits have demonstrated remarkable success in hybrid quantum circuits. However, most qubit architectures are limited to the GHz frequency range, severely…
Semiconductor quantum dots are useful for controlling and observing quantum states and can also be used as sensors for reading out quantum bits and exploring local electronic states in nanostructures. However, challenges remain for the…
Increasing the separation between semiconductor quantum dots offers scaling advantages by fa- cilitating gate routing and the integration of sensors and charge reservoirs. Elongated quantum dots have been utilized for this purpose in GaAs…
Detection of single-electron charges in solid-state nanodevices is a key technique in semiconductor quantum bit readout for quantum information processing and probing electronic properties of nanostructures. This detection is achieved using…
We demonstrate the use of radio-frequency (rf) resonators to measure the capacitance of nano-scale semiconducting devices in field-effect transistor configurations. The rf resonator is attached to the gate or the lead of the device.…
We provide a physical analysis of the charging and detection of the first few electrons in a laterally-coupled GaAs/AlGaAs quantum dot (LCQD) circuit with integrated quantum point contact (QPC) read-out. Our analysis is based on the…
The mass production and the practical number of cryogenic quantum devices producible in a single chip are limited to the number of electrical contact pads and wiring of the cryostat or dilution refrigerator. It is, therefore, beneficial to…
We present measurements on a quantum dot and a nearby, capacitively coupled, quantum point contact used as a charge detector. With the dot being weakly coupled to only a single reservoir, the transfer of individual electrons onto and off…
We report raster scan multiplexed charge-stability diagram measurements for tuning multiple gate-defined quantum dots in GaAs/AlGaAs heterostructures. We evaluate the charge sensitivity of the quantum point contact (QPC) in both radio…
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…
Superconducting resonators enable fast characterization and readout of mesoscopic quantum devices. Finding ways to perform measurements of interest on such devices using resonators only is therefore of great practical relevance. We report…
We demonstrate fast and ultrasensitive charge detection with a cavity-embedded Cooper pair transistor (cCPT) via dispersive readout of its Josephson inductance. We report a minimum charge sensitivity of $14$ $\mu e/\sqrt{\mathrm{Hz}}$ with…
A radio-frequency (rf) matching circuit with an in situ tunable varactor diode used for rf reflectometry measurements in semiconductor nanostructures is investigated and used to optimize the sample-specific chip design. The samples are…
The response of a single InGaAs quantum dot, embedded in a miniaturized charge-tunable device, to an applied GHz bandwidth electrical pulse is investigated via its optical response. Quantum dot response times of 1.0 \pm 0.1 ns are…
We study theoretically transitions of a double quantum-dot qubit caused by nonequilibrium charge fluctuations in a nearby quantum point contact (QPC) used as a detector. We show that these transitions are related to the fundamental…
A semiconductor quintuple quantum dot with two charge sensors and an additional contact to the center dot from an electron reservoir is fabricated to demonstrate the concept of scalable architecture. This design enables formation of the…
We report on charge detection in electrostatically-defined quantum dot devices in bilayer graphene using an integrated charge detector. The device is fabricated without any etching and features a graphite back gate, leading to high quality…