Broadband Quantum limited Traveling-Wave Parametric Amplifier based on a Superconducting Metamaterial Transmission Line

职务名称：基于超导超材料传输线的宽带量子限幅行波参量放大器非技术描述：人们对利用量子限幅放大器检测微弱微波信号重新产生了兴趣。 这样的放大器允许在射电天文学中进行超灵敏探测（如暗物质搜索或宇宙微波背景研究），光子数分辨率的探测器，超安全量子通信和超导量子比特的真实的时间监测。低水平信号的检测，特别是在单光子水平上的检测是具有挑战性的，其中需要具有受量子力学波动限制的噪声水平的放大器来进行令人满意的信噪比测量。在这个项目中，一种新型的行波参量放大器（TWPA）组成的可调谐超材料传输线，这将允许有效的参数放大的微弱信号在微波制度的宽带宽，利用低损耗超导电路的开发。构成所提出的放大器的超材料传输线可以被调谐为具有负折射率，这允许在非常短的长度上进行有效放大，这有助于降低噪声并促进可扩展性。参加这项研究的学生将接触到现代固态科学和工程中最先进的实验技术，并且还能够通过参加K-12学生和教师的外联活动来分享他们对科学和工程的热情。外展活动包括移动的原子力显微镜示范实验室，这些实验室被带到K-12 institutions.to，展示纳米科学概念。技术描述：目前最先进的TWPA设计主要基于约瑟夫森结的系列阵列，最初是在20世纪80年代初引入的。 这些设计的局限性阻碍了它们的广泛使用和采用。这些限制与：相位匹配，弱非线性，以及几倍于量子极限的过度噪声有关。在这项研究计划中，我们提出了一个完全不同的方法来相位匹配的TWPA。拟议的TWPA是由一个超材料传输线，这将允许有效的参数放大在微波制度利用低损耗超导电路的宽带宽。超材料传输线由磁阻挫非对称超导量子干涉器件耦合而成的独特网络构成。所提出的超材料传输线的折射率（阻抗）的原位可调谐性允许折射率的非线性分量从正调谐到负，这可以使弱信号与强泵浦相位匹配，并导致弱信号的有效参量放大。预期所提出的TWPA在宽带宽（5 GHz）上提供高增益（20 dB），同时保持噪声性能的量子限制。本研究的主要目的是：（1）制作TWPA原型;（2）表征TWPA的增益、带宽、动态范围和附加噪声;（3）验证TWPA的量子噪声特性;（4）研究TWPA在参数变化情况下的性能;（4）研究TWPA中导致噪声过大的损耗机制。

Title: Broadband Quantum Limited Traveling-Wave Parametric Amplifier based on a Superconducting Metamaterial Transmission LineNon-Technical Description:There has been renewed interest in utilizing quantum limited amplifiers for detection of weak microwave signals. Such amplifiers have allowed for ultra-sensitive detection in radio astronomy (such as dark matter searches or cosmic microwave background studies), detectors with photon number resolution, ultra-secure quantum communications, and real time monitoring of superconducting quantum bits. Detection of low level signals, particularly at the single photon level is challenging, where amplifiers which have noise levels which are limited by quantum mechanical fluctuations are required for a satisfactory signal-to-noise ratio measurement. In this project a novel traveling-wave parametric amplifier (TWPA) composed of a tunable metamaterial transmission line which will allow for efficient parametric amplification of a weak signal over a broad bandwidth in the microwave regime utilizing low-loss superconducting circuits is developed. The metamaterial transmission line which makes up the proposed amplifier can be tuned to have a negative refractive index which allows for efficient amplification over very short lengths, which aides in the reduction of noise and promotes scalability. Students participating in this research will be exposed to state-of-the-art experimental techniques in modern solid-state science and engineering, and will also be able to share their enthusiasm for science and engineering by participating in outreach activities to K-12 students and teachers. Outreach activities include mobile atomic force microscope demonstrative laboratory which are brought to K-12 institutions.to demonstrate nanoscience concepts.Technical Description:Present state-of-the-art TWPA designs have been primarily based on series arrays of Josephson junctions as originally introduced in the early 1980s. Limitations in these designs have prevented their wide-spread use and adoption. These limitations have to do with: phase matching, weak nonlinearities, and excessive noise several times the quantum limit. In this research program we propose to take an entirely different approach to phase matching in a TWPA. The proposed TWPA is composed of a metamaterial transmission line which will allow for efficient parametric amplification over a broad bandwidth in the microwave regime utilizing low-loss superconducting circuits. The metamaterial transmission line is composed of a unique network of coupled magnetically frustrated asymmetric superconducting quantum interference devices. The tunability of the refractive index (impedance) of the proposed metamaterial transmission line in situ allows for the nonlinear component of the refractive index to be tuned from positive to negative which can phase match a weak signal to a strong pump and result in efficient parametric amplification of the weak signal. The proposed TWPA is expected to deliver high gain ( 20 dB) over a broad bandwidth ( 5 GHz) while maintaining quantum limited in noise performance. The objectives of the proposed research are: (1) to fabricate prototype TWPAs (2) Characterize the gain, bandwidth, dynamic range, and added noise (3) Validate the quantum limited in noise nature of the TWPA (4) Investigate the performance of the TWPA in the presence of parameter variations (4) Study loss mechanisms in the TWPA which contribute to excessive noise.