Rights statement: Copyright 2020 American Institute of Physics. The following article appeared in Journal of Applied Physics, 127, 2020 and may be found at https://doi.org/10.1063/5.0005886 This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.
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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Sensitive radio-frequency read-out of quantum dots using an ultra-low-noise SQUID amplifier
AU - Schupp, F J
AU - Vigneau, F.
AU - Wen, Yutian
AU - Mavalankar, A
AU - Griffiths, J. P.
AU - Jones, G. A. C.
AU - Farrer, I.
AU - Ritchie, David
AU - Smith, C. G.
AU - Camenzind, L. C.
AU - Yu, L.
AU - Zumbühl, Dominik
AU - Briggs, G. Andrew D.
AU - Laird, Edward
N1 - Copyright 2020 American Institute of Physics. The following article appeared in Journal of Applied Physics, 127, 2020 and may be found at https://doi.org/10.1063/5.0005886 This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.
PY - 2020/6/29
Y1 - 2020/6/29
N2 - Fault-tolerant spin-based quantum computers will require fast and accurate qubit readout. This can be achieved using radio-frequency reflectometry given sufficient sensitivity to the change in quantum capacitance associated with the qubit states. Here, we demonstrate a 23-fold improvement in capacitance sensitivity by supplementing a cryogenic semiconductor amplifier with a SQUID preamplifier. The SQUID amplifier operates at a frequency near 200 MHz and achieves a noise temperature below 600 mK when integrated into a reflectometry circuit, which is within a factor 120 of the quantum limit. It enables a record sensitivity to capacitance of 0.07 aF/ \sqrt{Hz}. The setup is used to acquire charge stability diagrams of a gate-defined double quantum dot in a short time with a signal-to-noise ration of about 38 in 1 μs of integration time.
AB - Fault-tolerant spin-based quantum computers will require fast and accurate qubit readout. This can be achieved using radio-frequency reflectometry given sufficient sensitivity to the change in quantum capacitance associated with the qubit states. Here, we demonstrate a 23-fold improvement in capacitance sensitivity by supplementing a cryogenic semiconductor amplifier with a SQUID preamplifier. The SQUID amplifier operates at a frequency near 200 MHz and achieves a noise temperature below 600 mK when integrated into a reflectometry circuit, which is within a factor 120 of the quantum limit. It enables a record sensitivity to capacitance of 0.07 aF/ \sqrt{Hz}. The setup is used to acquire charge stability diagrams of a gate-defined double quantum dot in a short time with a signal-to-noise ration of about 38 in 1 μs of integration time.
U2 - 10.1063/5.0005886
DO - 10.1063/5.0005886
M3 - Journal article
VL - 127
JO - Journal of Applied Physics
JF - Journal of Applied Physics
SN - 0021-8979
M1 - 244503
ER -