Rights statement: Copyright 2020 American Institute of Physics. The following article appeared in Journal of Applied Physics, 127, 24 2020 and may be found at http://dx.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 radiofrequency readout of quantum dots using an ultra-low-noise SQUID amplifier
AU - Schupp, F.J.
AU - Vigneau, F.
AU - Wen, Y.
AU - Mavalankar, A.
AU - Griffiths, J.
AU - Jones, G.A.C.
AU - Farrer, I.
AU - Ritchie, D.A.
AU - Smith, C.G.
AU - Camenzind, L.C.
AU - Yu, L.
AU - Zumbühl, D.M.
AU - Briggs, G.A.D.
AU - Ares, N.
AU - Laird, E.A.
N1 - Copyright 2020 American Institute of Physics. The following article appeared in Journal of Applied Physics, 127, 24 2020 and may be found at http://dx.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 - 2020/6/28
Y1 - 2020/6/28
N2 - Fault-tolerant spin-based quantum computers will require fast and accurate qubit read out. This can be achieved using radiofrequency 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 200MHz and achieves a noise temperature below 600mK when integrated into a reflectometry circuit, which is within a factor 120 of the quantum limit. It enables a record sensitivity to capacitance of0.07 mml:mspace width=".1em"mml:mspaceaF / mml:msqrtHzmml:msqrt. 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 in1 mml:mspace width=".1em"mml:mspace mus of integration time.
AB - Fault-tolerant spin-based quantum computers will require fast and accurate qubit read out. This can be achieved using radiofrequency 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 200MHz and achieves a noise temperature below 600mK when integrated into a reflectometry circuit, which is within a factor 120 of the quantum limit. It enables a record sensitivity to capacitance of0.07 mml:mspace width=".1em"mml:mspaceaF / mml:msqrtHzmml:msqrt. 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 in1 mml:mspace width=".1em"mml:mspace mus of integration time.
KW - Capacitance
KW - Molluscs
KW - Nanocrystals
KW - Qubits
KW - Reflection
KW - Reflectometers
KW - Semiconductor quantum dots
KW - Signal to noise ratio
KW - Charge stability
KW - Cryogenic Semiconductors
KW - Double quantum dots
KW - Integration time
KW - Noise temperature
KW - Quantum capacitance
KW - Radio frequencies
KW - Signal to noise rations
KW - SQUIDs
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
IS - 24
M1 - 0005886
ER -