论文标题
宽带约瑟夫森参数隔离器
Wideband Josephson Parametric Isolator
论文作者
论文摘要
建立基于量子的量子计算机所需的低温硬件需要各种微波组件。这些要素包括微波耦合器，过滤器，放大器和循环器/隔离器。传统上以离散组件的形式实现，该外围硬件的集成是为了减少整体足迹，热负载和增加的噪声，这是对以Qubit计数攀升100+标记的现代量子处理器的关键挑战。通常在读取链中使用的基于铁素体的微波隔离器将Qubits和resonator从读取电子设备中解脱出来，它仍然是数量最大的设备之一，但仍用作离散组件。在这里，我们提出了一个替代两个端口隔离电路，该电路源自直流超导量子干扰装置（DC-Squid）。使用通量调节的dc- squid的三波微波混合特性来实现非转向透射率。我们表明，当将多个DC平台嵌入多极式倒滤滤器结构中时，源自DC-Squids的通量泵送的三波混合可以提供定向微波功率流。对于三极滤波器设备，我们在600 MHz带宽上实验证明了大于15 dB的方向性。
The cryogenic hardware required to build a superconducting qubit based quantum computer demands a variety of microwave components. These elements include microwave couplers, filters, amplifiers, and circulators/isolators. Traditionally implemented as discrete components, integration of this peripheral hardware, in an effort to reduce overall footprint, thermal load, and added noise, is a key challenge to scaling modern quantum processors with qubit counts climbing over the 100+ mark. Ferrite--based microwave isolators, generally employed in the readout chain to decouple qubits and resonators from readout electronics, persist as one of the volumetrically largest devices still utilized as discrete components. Here we present an alternative two--port isolating integrated circuit derived from the DC Superconducting Quantum Interference Device (DC-SQUID). Non-reciprocal transmission is achieved using the three-wave microwave mixing properties of a flux-modulated DC--SQUID. We show that when multiple DC-SQUIDs are embedded in a multi--pole admittance inverting filter structure, the three-wave mixing derived from the flux pumping of the DC-SQUIDs can provide directional microwave power flow. For a three--pole filter device, we experimentally demonstrate a directionality greater than 15 dB over a 600 MHz bandwidth.
