One-Way Quantum Repeater with Rare-Earth-Ions Doped in Solids

Quantum repeaters are proposed to overcome exponential photon loss over distance in fibers. One-way quantum repeaters eliminate the need for two-way classical communications, which can potentially outperform quantum memory based quantum repeaters. I propose that rare-earth-ions doped in solids and coupled with nano-cavity can be used to generate photonic cluster state efficiently, which serve as good platforms for one-way quantum repeater nodes. In addition, I propose a multiplexed scheme of photonic tree cluster state generation with multiple quantum emitters. With less than 100 quantum emitters, secret key rates can reach the order of MHz over a few thousand kilometers. This proposal is especially useful for generating large scale photonic cluster state, which is essential for correcting operational errors during processing in quantum repeater nodes.