Direct spectrum analysis using a threshold detector with application to a superconducting circuit
Direct spectrum analysis using a threshold detector with application to a superconducting circuit
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DOI：
10.1088/1367-2630/16/5/055010
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发表时间：
2014-05-14
影响因子：
3.3
通讯作者：
Meeson, P. J.
中科院分区：
文献类型：
--
作者：
Ithier, G.;Tancredi, G.;Meeson, P. J.
我们介绍了一种利用阈值探测器进行噪声谱分析的新的定量理论框架，并将其应用于超导器件：约瑟夫森分叉放大器。我们表明，这个新的框架提供了对环境噪声频谱的直接访问，其灵敏度接近于弱连续测量的标准量子极限。此外，频谱的可用频率范围原则上仅受谐振模式的振铃时间限制。这种片内噪声探测器是非耗散的，探测功率很低，可以在低温(T<；15MK)下工作。我们利用这项技术来测量我们的设备的频率波动，并发现了与介电来源兼容的幅度和频谱的低频噪声。
We introduce a new and quantitative theoretical framework for noise spectral analysis using a threshold detector, which is then applied to a superconducting device: the Josephson bifurcation amplifier. We show that this new framework provides direct access to the environmental noise spectrum with a sensitivity approaching the standard quantum limit of weak continuous measurements. In addition, the accessible frequency range of the spectrum is, in principle, limited only by the ring down time of the resonant mode. This on-chip noise detector is non-dissipative and works with low probing powers, allowing it to be operated at low temperatures (T < 15 mK). We exploit this technique for measuring the frequency fluctuations of our device and find a low frequency noise with an amplitude and spectrum compatible with a dielectric origin.