Rephasing spectral diffusion in time-bin spin-spin entanglement protocols

Understand

Generating high fidelity spin-spin entanglement is an essential task of quantum repeater networks for the distribution of quantum information across long distances.

• Solid-state based spin-photon interfaces are promising candidates to realize nodes of a quantum network, but are often limited by spectral diffusion of the optical transition, which results in phase errors on the entangled states.
• Here, we introduce a method to correct phase errors from quasi-static frequency fluctuations after the entangled state is generated, by shelving the emitters in the excited state to refocus the unknown phase.
• For quasi-static frequency fluctuations, the fidelity is determined only by the lifetime of the excited state used for shelving, making it particularly suitable for systems with a long-lived shelving state with correlated spectral diffusion.