Nonlinear superconducting metamaterials

超材料是人工和工程结构，使物质与电磁波的独特相互作用。使用超导体作为超材料中正常金属的替代品，可以将损耗降低几个数量级，缩小超原子的尺寸，并实现可调的工作频率。此外，超导元原子提供了强非线性和多动力学状态，导致新的功能的超材料。我们提出了一个实验研究的超导材料的非线性特性采用约瑟夫森结。我们将研究大型一维和二维阵列的频率可调超导微波谐振器。我们将探讨最近发现的多稳定的动力学状态在一个由SQUID为基础的元原子组成的介质。特别是，我们将设计，制造和测量紧凑的基于铌的约瑟夫森结谐振器，以探索其强非线性效应和微波频率下的开关。这样的元原子网络开辟了一个机会，第一次，调查参数特性的分布式约瑟夫森介质，而不是一个单一的设备。使用这样的有源参量介质，我们的目标是展示新的功能，如宽带无线混频和信号放大的电磁波。

Metamaterials are artificial and engineered structures that enable unique interactions of matter with electromagnetic waves. Using superconductors as a replacement for normal metals in metamaterials allows reducing losses by several orders of magnitude, shrinking the size of the meta-atoms and achieving a tunable frequency of operation. Moreover, superconducting meta-atoms offer strong nonlinearity and multiple dynamical states leading to new functions of metamaterials. We propose an experimental study of the nonlinear properties of superconducting metamaterials employing Josephson junctions. We will study large one- and two-dimensional arrays of frequency-tunable superconducting microwave resonators. We will explore recently discovered multi-stable dynamical states in a medium consisting of SQUID-based meta-atoms. In particular, we will design, fabricate and measure compact niobium-based Josephson junction resonators to explore their strong nonlinear effects and switching at microwave frequencies. Networks of such meta-atoms open up an opportunity, for the first time, to investigate parametric properties of a distributed Josephson medium rather than that of a single device. Using such an active parametric medium, we aim at demonstrating novel functionalities for travelling electromagnetic waves such as broadband wireless mixing and signal amplification.