We report on the use of a kinetic-inductance traveling-wave parametric amplifier (KITWPA) as the first amplifier in the readout chain of a microwave superconducting quantum interference device (SQUID) multiplexer (μmux). This μmux is designed to multiplex signals from arrays of low temperature detectors, such as superconducting transition-edge sensor microcalorimeters. When modulated with a periodic flux-ramp to linearize the SQUID response, the flux noise improves, on average, from 1.6 μΦ0/Hz with the KITWPA off to 0.77 μΦ0/Hz with the KITWPA on. When statically biasing the μmux to the maximally flux-sensitive point, the flux noise drops from 0.45 μΦ0/Hz to 0.2 μΦ0/Hz. We validate this new readout scheme by coupling a transition-edge sensor microcalorimeter to the μmux and detecting background radiation. The combination of μmux and KITWPA provides a variety of new capabilities including improved detector sensitivity and more efficient bandwidth utilization.

中文翻译：

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使用动感行波参量放大器改进微波 SQUID 多路复用器读出

我们报告了使用动感行波参量放大器 (KITWPA) 作为微波超导量子干涉器件 (SQUID) 多路复用器 (μmux) 读出链中的第一个放大器。该 μmux 设计用于多路复用来自低温检测器阵列的信号，例如超导过渡边缘传感器微量热计。当使用周期性磁通斜坡调制以线性化 SQUID 响应时，磁通噪声平均从 KITWPA 关闭时的 1.6 μΦ0/Hz 改善到 KITWPA 开启时的 0.77 μΦ0/Hz。当将 μmux 静态偏置到最大磁通敏感点时，磁通噪声从 0.45 μΦ0/Hz 降至 0.2 μΦ0/Hz。我们通过将过渡边缘传感器微量热计耦合到 μmux 并检测背景辐射来验证这种新的读出方案。