Fast Single-Charge Sensing with an rf Quantum Point Contact

Abstract

We report high-bandwidth charge sensing measurements using a GaAs quantum point contact embedded in a radio frequency impedance matching circuit (rf-QPC). With the rf-QPC biased near pinch-off where it is most sensitive to charge, we demonstrate a conductance sensitivity of 5x10^(-6) e^(2)/h Hz^(-1/2) with a bandwidth of 8 MHz. Single-shot readout of a proximal few-electron double quantum dot is investigated in a mode where the rf-QPC back-action is rapidly switched.

related papers available at http://marcuslab.harvard.edu

References in corpus (1)

• Quantum-Limited Measurement and Information in Mesoscopic Detectors

Cited by in corpus (10)

• Frequency-selective single photon detection using a double quantum dot
• Electron counting in quantum dots
• Measurement of Temporal Correlations of the Overhauser Field in a Double Quantum Dot
• Weak values of electron spin in a double quantum dot
• Electron counting with a two-particle emitter
• Nuclear spin dynamics and Zeno effect in quantum dots and defect centers
• Measuring current by counting electrons in a nanowire quantum dot
• Detecting THz current fluctuations in a quantum point contact using a nanowire quantum dot
• Time-resolved charge detection with cross-correlation techniques
• Model for monitoring of a charge qubit using a radio-frequency quantum point contact including experimental imperfections