Recent technical advances have sparked renewed interest in physical systems that couple simultaneously to different parts of the electromagnetic spectrum, thus enabling transduction of signals between vastly different frequencies at the level of single quanta. Such hybrid systems have demonstrated frequency conversion of classical signals and have the potential of enabling quantum state transfer, e.g., between superconducting circuits and traveling optical signals. This article describes a simple approach for the theoretical characterization of the performance of quantum transducers. Given that, in practice, one cannot attain ideal one-to-one quantum conversion, we explore how imperfections impact the performance of the transducer in various scenarios. We quantify how knowledge of the well-established transducer parameters signal transfer efficiency η and added noise N suffices to assess its performance in a variety of transduction schemes ranging from classical si...

中文翻译：

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量子换能器的品质因数

最近的技术进步激发了人们对同时耦合到电磁频谱不同部分的物理系统的兴趣，从而可以在单个量子级的不同频率之间转换信号。这样的混合系统已经证明了经典信号的频率转换，并且具有实现例如在超导电路和传播的光信号之间进行量子状态转移的潜力。本文介绍了一种简单的方法来对量子换能器的性能进行理论表征。鉴于在实践中，人们无法实现理想的一对一量子转换，因此我们探索了缺陷在各种情况下如何影响换能器的性能。