Long-distance entanglement sharing using hybrid states of discrete and continuous variables
Soumyakanti Bose, Jaskaran Singh, Adán Cabello, Hyunseok Jeong
Abstract
We introduce a feasible scheme to produce high-rate long-distance entanglement that uses hybrid entanglement between continuous variables (CVs) and discrete variables (DVs). We show that hybrid entanglement can effectively remove the experimental limitations of existing CV and DV systems to produce long-range entanglement. We benchmark the resulting DV entangled states using an entanglement-based-quantum-key-distribution protocol. We show, using hybrid entangled states, that entanglement-based quantum key distribution is possible with standard telecommunication fibers for 300 km. The key idea is the use of the CV part, which can be adjusted to be robust regarding photon losses, for increasing the transmission distance, and the use of the DV part for achieving high secure key rates. Our results show that hybrid entangled states provide a clear advantage for practical generation of long-distance and high-rate entanglement that may lead to further applications in quantum information processing.