Long-distance distribution of qubit-qubit entanglement using Gaussian-correlated photonic beams

We investigate the deterministic generation and distribution of entanglement in large quantum networks by driving distant qubits with output fields a nondegenerate parametric amplifier. In this setting, amplifier produces continuous Gaussian two-mode squeezed state, which acts as quantum-correlated reservoir for relaxes them into highly entangled steady state. Here we are interested maximal amount optimal rates that can be achieved scheme under realistic conditions taking, particular, finite bandwidth, waveguide losses, propagation delays account. By combining exact numerical simulations full network approximate analytic results, predict working point corresponding qubit-qubit various conditions. Our findings show passive conversion discrete-variable offers robust experimentally very attractive approach operating optical, microwave, or hybrid networks, efficient amplifiers currently developed.