Correlated noise can be beneficial to quantum transducers

Quantum systems are inherently susceptible to noise—a notorious factor that induces decoherence and limits the performance of quantum applications. To mitigate its detrimental effects, various techniques have been developed, including cryogenic cooling, bath engineering, and quantum error correction. In this Letter, we demonstrate that by exploiting noise correlations in coupled quantum systems, the overall impact of noise can be significantly suppressed. Specifically, in a piezo-optomechanical-based microwave-optical quantum transducer, correlations between the noise affecting the acoustic and electrical modes can lead to substantial noise reduction, thereby enhancing the performance of quantum transduction. This reduction is primarily governed by the phase of the piezomechanical coupling and is also influenced by system parameters such as the coupling ratio and mode cooperativity. Since these parameters simultaneously affect the signal transmissivity, they must be optimized to achieve the transducer’s optimal performance. Our work provides a systematic framework for this optimization, offering a guidance for practical designs.