arXiv 1406.01972014-06-01cond-mat.mes-hall

自组织噪声压缩模式的约瑟夫森结微波放大器

Josephson junction microwave amplifier in self-organized noise compression mode

Pasi Lähteenmäki, Visa Vesterinen, Juha Hassel, Heikki Seppä, Pertti Hakonen

备注：: 15 pages, 6 figures, supplementary information found in the published version
发表信息：: Scientific Reports 2, 276 (2012)

摘要：

相位保持放大器在频率$ω/2π$处的基本噪声极限是标准量子极限$T_{q}=\hbar ω/2k_{B}$。在微波范围内，最好的候选者是基于超导量子干涉器件的放大器（在700 MHz时达到噪声温度$T_{n} \sim 1.8 T_{q}$）和非简并参量放大器（在8 GHz时达到接近量子极限$T_{n}\approx T_{q}$的噪声水平）。介绍了一种基于选择性阻尼约瑟夫森结负阻特性的新型放大器。我们的放大器的噪声性能受到从约瑟夫森振荡区到信号频率的量子噪声的混合的限制。由于工作点的自组织，测量产生了接近量子限制的操作，$T_{n}=(3.2\pm 1.0) T_{q}$在2.8 GHz。模拟描述了我们的设备的特点，以及表明宽带操作的潜力。

英文摘要：

The fundamental noise limit of a phase-preserving amplifier at frequency $ω/2π$ is the standard quantum limit $T_{q}=\hbar ω/2k_{B}$. In the microwave range, the best candidates have been amplifiers based on superconducting quantum interference devices (reaching the noise temperature $T_{n} \sim 1.8 T_{q}$ at 700 MHz), and non-degenerate parametric amplifiers (reaching noise levels close to the quantum limit $T_{n}\approx T_{q}$ at 8 GHz). We introduce a new type of an amplifier based on the negative resistance of a selectively damped Josephson junction. Noise performance of our amplifier is limited by mixing of quantum noise from Josephson oscillation regime down to the signal frequency. Measurements yield nearly quantum-limited operation, $T_{n}=(3.2\pm 1.0) T_{q}$ at 2.8 GHz, owing to self-organization of the working point. Simulations describe the characteristics of our device well and indicate potential for wide bandwidth operation.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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英文摘要：

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