Intra-band entanglement-assisted cavity electro-optic quantum transducer

Abstract: Quantum transduction is a key technology for connecting different quantum technologies across varied frequencies. However, it remains a major challenge to overcome the high threshold for achieving positive capacity of traditional quantum transduction channels. Recently, an entanglement-assisted transducer was proposed based on a cavity-optic system [Opt. Quantum 2, 475 (2024)], where a modified bosonic loss channel was obtained, and the transduction efficiency can be enhanced by properly tuning the squeezing parameters. In this paper, we further identify three types of quantum channels enabled by this design, offering additional options for implementing the proposed transduction schemes. Compared to the transducers without entanglement assistance, the scheme also shows a great enhancement in the conversion bandwidth for achieving high quantum capacity, further increasing its value in practical applications.