In superconducting quantum computing, qubit state information is conveyed via low-power microwave fields. As such, ultralow-noise microwave amplification plays a central role in measuring these fields to quickly and accurately infer the qubit state. To this end, parametric amplification, once a well-known concept for low-noise amplifiers during the 1960s and 1970s, has become the leading technology for enabling highly efficient microwave measurements of these quantum circuits. While current research efforts have elements in common with much earlier work, there are some important differences that distinguish this new generation of amplifiers. Here, we try to give an overview of what this excitement is about, how these devices work, and where there are opportunities for improvement.

中文翻译：

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超导参量放大器：约瑟夫森参量放大器的最新技术

在超导量子计算中，量子位状态信息是通过低功率微波场传输的。因此，超低噪声微波放大在测量这些场以快速准确地推断量子位状态方面起着核心作用。为此，参量放大曾是 1960 年代和 1970 年代众所周知的低噪声放大器概念，现已成为实现这些量子电路高效微波测量的领先技术。虽然当前的研究工作与更早的工作有一些共同点，但有一些重要的差异可以区分新一代放大器。在这里，我们尝试概述这种兴奋是什么，这些设备如何工作，以及哪里有改进的机会。