Faithful conversion of quantum signals between microwave and optical frequency domains is crucial for building quantum networks based on superconducting circuits. Optoelectromechanical systems, in which microwave and optical cavity modes are coupled to a common mechanical oscillator, are a promising route towards this goal. In these systems, efficient, low-noise conversion is possible using a mechanically dark mode of the fields, but the conversion bandwidth is limited to a fraction of the cavity linewidth. Here, we show that an array of optoelectromechanical transducers can overcome this limitation and reach a bandwidth that is larger than the cavity linewidth. The coupling rates are varied in space throughout the array so that the mechanically dark mode of the propagating fields adiabatically changes from microwave to optical or vice versa. This strategy also leads to significantly reduced thermal noise with the collective optomechanical cooperativity being the relevant figure of merit. Finally, we demonstrate that the bandwidth enhancement is, surprisingly, largest for small arrays; this feature makes our scheme particularly attractive for state-of-the-art experimental setups.

在微波和光频域之间进行量子信号的真实转换对于构建基于超导电路的量子网络至关重要。将微波和光腔模式耦合到普通机械振荡器的光机电系统是实现该目标的有希望的途径。在这些系统中，可以使用场的机械暗模式进行有效的低噪声转换，但是转换带宽被限制为腔体线宽的一小部分。在这里，我们表明，光电换能器阵列可以克服此限制，并达到大于腔体线宽的带宽。耦合速率在整个阵列的空间中是变化的，因此，传播场的机械暗模式从微波绝热地改变为微波，反之亦然。这种策略还可以显着降低热噪声，而集体的光机械合作性是相关的优点。最后，我们证明了带宽提高对于小型阵列而言是最大的。此功能使我们的方案对于最新的实验装置特别具有吸引力。