Researchers engineered high-purity, (111)-oriented diamond with controlled carbon-13 and low nitrogen, then used 50 Hz noise mitigation and CPMG dynamical decoupling to extend a single NV-center electron spin’s coherence to 11.2(8) seconds while retaining a near-lifetime-limited optical linewidth of 16.9(4) MHz. The study shows that long spin coherence and coherent optical transitions can coexist in diamond, with implications for quantum-network nodes and sensing.
