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arXiv · 0707.2946

Fast Single-Charge Sensing with an rf Quantum Point Contact

D. J. Reilly·C. M. Marcus·M. P. Hanson·A. C. Gossard
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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.

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D. J. Reilly, C. M. Marcus, M. P. Hanson, A. C. Gossard. 2007-08-28. Fast Single-Charge Sensing with an rf Quantum Point Contact. https://doi.org/10.1063/1.2794995

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