Collaborative Research: Kinetic Inductance in Superconducting Nanowire Microwave Devices

合作研究：超导纳米线微波器件中的动感电感

• 批准号: 2000743
• 负责人: Karl Berggren
• 金额: $ 38.3万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2000743&HistoricalAwards=false
• 关键词: Collaborative; Research; Kinetic; Inductance; Superconducting

Proposal Title:Collaborative Research: Kinetic Inductance in Superconducting Nanowire Microwave DevicesNon-Technical AbstractSuperconducting nanowires can have a kinetic inductance that is several orders of magnitude larger than their magnetic inductance. As a result, high frequency signals on the nanowire experience significant spatial compression as well as a significant reduction in their velocity. The kinetic inductance also varies nonlinearly as a function of the current, creating an opportunity for realizing nonlinear phenomena with extremely minimal dissipation. Through a combination of theory, modeling, and experiment, this project will study these effects in different superconducting nanowire materials and geometries. The understanding gained from these studies will be applied to design new types of ultra-compact microwave devices, which will then be fabricated and characterized. Such devices can serve as important building blocks for the development of more complex systems based on superconducting circuits such as single-photon imagers and quantum computers. This collaborative project brings together groups at Massachusetts Institute of Technology and the University of North Florida, an undergraduate-education focused university, to conduct the proposed research and educational activities, combining the best aspects of both institutions. In particular, the involvement of the University of North Florida creates additional opportunities for undergraduates from diverse backgrounds to participate in the research.Technical AbstractThe goal of this project is to create a new superconducting nanowire device platform that can serve as the basis of a monolithic superconducting nanowire microwave integrated circuit technology. This goal will be pursued through four approaches. The first approach is based on exploring materials and geometries that maximize the nanowire's kinetic inductivity, which will result in extremely large characteristic impedances ( 10 kohm) along with slow signal velocities and large spatial compression of the signal wavelengths. Such high impedances create strong decoupling from the environment and have potential applications ranging from the readout of superconducting nanowire single-photon detectors to the design of quantum bits. The second approach will be to fabricate nanowires on extremely high permittivity substrates such as strontium titanate, which has been shown to have a relative permittivity as high as 10,000 at low temperature. This extremely large permittivity will significantly boost the capacitance, bringing the characteristic impedance of high-inductance nanowires close to 50 kohm while simultaneously achieving ultra-slow signal velocities and ultra-compressed signal wavelengths. A 50 kohm impedance is critical to coupling with conventional microwave circuitry. The third approach will focus on understanding and exploiting the nonlinear current-dependence of kinetic inductance in order to create new types of nanowire-based nonlinear microwave devices. Examples of such devices include mixers, tunable couplers, switches, and parametric amplifiers. In order to understand these devices, the project will seek to address fundamental questions such as how quickly the nanowire's kinetic inductance can be modulated, how much loss is associated with this modulation, and how the nonlinearity and the loss depend on the signal power. The fourth approach will leverage the results generated in the first three approaches to develop more complex nanowire-based devices and circuits.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

提案标题：协作研究：超导微波设备中的动力学电感纳米型纳米线可以具有比其磁性电感大的数量级的动力学电感。结果，纳米线上的高频信号经历了显着的空间压缩以及速度的显着降低。动力电感也随电流的函数而非线性变化，从而为实现非线性现象而产生的机会极少。通过理论，建模和实验的结合，该项目将在不同的超导纳米线材料和几何形状中研究这些效果。从这些研究中获得的理解将应用于设计新型的超紧凑型微波设备，然后将其制造和表征。这些设备可以作为基于超导电路（例如单光子成像仪和量子计算机）开发更复杂系统的重要组成部分。这个合作项目将马萨诸塞州理工学院的小组和北佛罗里达大学（一所专注于教育的大学）汇集在一起​​，以结合了这两个机构的最佳方面。特别是，北佛罗里达大学的参与为来自不同背景的大学生创造了更多的机会参加研究。技术摘要该项目的目标是创建一个新的超导纳米式设备平台，该平台可以作为单层超导纳米型微型电路集成电路技术的基础。这个目标将通过四种方法实现。第一种方法是基于探索材料和几何形状，从而最大程度地提高纳米线的动力学能力，这将导致极大的特征阻碍（10 KOHM）以及慢速信号速度和信号波长的大空间压缩。如此高的阻抗会与环境产生强大的脱钩，并具有潜在的应用，从超导纳米线单光子探测器的读数到量子位的设计。第二种方法是在极高的介电常数底物（如钛酸锶）上构建纳米线，该型钛酸锶的相对介电常数在低温下具有高达10,000的相对介电常数。这种极大的介电常数将显着提高电容，从而使高电感纳米线的特征阻抗接近50 koHm，同时达到超低信号速度和超压缩信号波长。 50 KOHM阻抗对于与常规微波电路耦合至关重要。第三种方法将着重于理解和利用动力学电感的非线性电流依赖性，以创建新型的基于纳米线的非线性微波设备。此类设备的示例包括混合器，可调耦合器，开关和参数放大器。为了理解这些设备，该项目将寻求解决基本问题，例如纳米线的动力电感可以被调节的速度，与此调制的损失有多少相关，以及非线性和损失如何取决于信号功率。第四种方法将利用前三种方法中产生的结果来开发更复杂的基于纳米线的设备和电路。该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和更广泛的影响评估标准，被认为值得通过评估。

项目成果

Compact and Tunable Forward Coupler Based on High-Impedance Superconducting Nanowires

• DOI: 10.1103/physrevapplied.15.024064
• 发表时间: 2020-11
• 期刊: arXiv: Applied Physics
• 作者: M. Colangelo;Di Zhu;D. Santavicca;B. Butters;J. Bienfang;K. Berggren