Extended Data Fig. 6: Lifetime-limited entanglement using the dynamic rephasing protocol.

After heralding an entangled state between Ions 1 and 2 and applying the dynamic rephasing protocol described in the main text, the entangled state coherence is probed via a measurement of the X-basis parity expectation value, \(\langle \widehat{X}\widehat{X}\rangle \), correlated with the photon emission time, t₀. The coherence oscillates at the relative difference in driving laser frequencies, \(\Delta {\widetilde{\omega }}_{12}\), and undergoes an exponential decay with a 1/e timescale of 970 ± 30 ns, limited by the Purcell-enhanced optical lifetimes of the two ions. Markers and solid lines correspond to experimental data and simulations, respectively, as detailed in Supplementary Information section VII.