Fast charge sensing of a cavity-coupled double quantum dot using a Josephson parametric amplifier
Fast charge sensing of a cavity-coupled double quantum dot using a Josephson parametric amplifier
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DOI：
10.1103/physrevapplied.4.014018
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发表时间：
2015-02
期刊：
影响因子：
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通讯作者：
J. Stehlík;Y. Liu;C. Quintana;C. Eichler;T. Hartke;J. Petta
中科院分区：
文献类型：
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作者：
J. Stehlík;Y. Liu;C. Quintana;C. Eichler;T. Hartke;J. Petta
我们演示了耦合到超导谐振器的双量子点（DQD）的快速读出。在非线性工作模式下利用参量放大，与参量放大器关闭的情况相比，我们将信噪比（SNR）提高了2000倍。积分时间为400 ns时，信噪比为76。通过研究SNR作为积分时间的函数，我们提取出8 x 10^{-5} e/root（Hz）的等效电荷灵敏度。高SNR使我们能够在短短20 ms内获得DQD电荷稳定性图。在如此高的数据速率下，可以在实时“视频模式”下获得电荷稳定性图，从而实现DQD约束电位的真实的时间调谐。
We demonstrate fast readout of a double quantum dot (DQD) that is coupled to a superconducting resonator. Utilizing parametric amplification in a nonlinear operational mode, we improve the signal-to-noise ratio (SNR) by a factor of 2000 compared to the situation with the parametric amplifier turned off. With an integration time of 400 ns we achieve a SNR of 76. By studying SNR as a function of the integration time we extract an equivalent charge sensitivity of 8 x 10^{-5} e/root(Hz). The high SNR allows us to acquire a DQD charge stability diagram in just 20 ms. At such a high data rate, it is possible to acquire charge stability diagrams in a live "video-mode," enabling real time tuning of the DQD confinement potential.