Multipartite high-dimensional entangled state generation through soliton-induced dynamical Casimir effect on a chip.

An integrated photonic approach for complex quantum state generation through dynamical Casimir effect (DCE) is demonstrated. This approach provides a scheme to realize multipartite high-dimensional entangled states in the microwave (MW) and terahertz (THz) regimes, through the modulation in a MW-resonator coupled to an optical microresonator supporting temporal optical solitons. The states at the MW-resonator evolve from the ground state, realizing real-photons from the virtual photons at the ground state. The periodic modulation of the MW-resonator through a Kerr-induced refractive index change in the optical microresonator, along with the localized spatial distribution of the dissipative Kerr solitons (DKSs), enables photon-pair generation and inter-mode coupling at the MW-resonator. This allows generating highly persistent multipartite high-dimensional entangled states in a wide range of spectrum. The proposed approach paves the way for a hybrid integrated platform for generation of multipartite entangled qudits (high-dimensional qubits) at the MW and THz regimes using highly coherent ultra-short optical pulses in a monolithic integrated platform. This architecture can act as an entangled state source, as a necessary resource for exploiting a wide range of quantum protocols from fault-tolerant computing to enhanced sensing and teleportation.