Heralding High Fidelity Entanglement Between Imperfect Artificial Atoms

Color centers in diamond have emerged as excellent candidates for quantum networks. However, despite their stable optical properties, residual spectral dephasing and diffusion still limit the achievable fidelity of heralded entanglement. Here, we address this problem through a new single-photon entanglement protocol that uses detuned optical coupling to spin-dependent optical transitions. Our calculations include entanglement distillation and are compared to other leading entanglement protocols. Estimates based on present-day technology indicate that this protocol enables entanglement fidelity in excess of 99% for leading diamond color centers.