Researchers stored telecom-heralded single photons for up to 180 microseconds in a solid-state quantum memory while preserving nonclassical correlations, a record for this type of absorptive memory using spin rephasing. The system combines an atomic frequency comb with radiofrequency pulses that reverse spin dephasing, allowing the collective atomic excitation carrying quantum information to recover its coherence. Classical light remained stored for about 3 milliseconds, suggesting that better magnetic-field control could eventually push single-photon storage much farther toward the timescales needed for practical quantum repeaters. A future quantum internet will need something today’s internet takes for granted: the ability to hold information while distant parts of a network catch up. Researchers in Spain have now demonstrated a solid-state quantum memory that stores individual photons for substantially longer than previously achieved with this kind of system. The device preserved nonclassical correlations for as long as 180 microseconds, enough time for light to travel an equivalent fiber distance of roughly 36 kilometers. The work, led by researchers at ICFO in Barcelona, was published in Physical Review Letters. The …