Switchable bipartite and genuine tripartite entanglement via an optoelectromechanical interface*

Controllable multipartite entanglement is a crucial element in quantum information processing. Here we present a scheme that generates switchable bipartite and genuine tripartite entanglement between microwave and optical photons via an optoelectromechanical interface, where microwave and optical cavities are coupled to a mechanical mode with controllable coupling constants. We show that bipartite entanglement can be generated and switched between designated output photons by tuning an effective gauge phase between the coupling constants to the “sweet spots”. The bipartite entanglement, characterized by the entanglement of formation, is robust against the mechanical noise and the signal loss to the mechanical mode under the impedance-matching condition. When the gauge phase is tuned away from the “sweet spots,” genuine tripartite entanglement can be generated and verified with homodyne measurement on the quadratures of the output fields. Our result can lead to the implementation of controllable and robust multipartite entanglement in hybrid quantum systems operated in distinctively different frequencies.
1. C. Jiang et al., Phys. Rev. A 101, 042320 (2020)