Spin-rephased quantum memory stores/ recalls individual optical photons furthering long-distance quantum repeaters/ quantum Internet

https://www.eurekalert.org/news-releases/1145475

"scalable,solid-state, counteracts decoherence, by applying targeted RF pulses to praseodymium-doped crystal using atomic frequency comb protocol, reversing phase drift/ restoring stored optical excitation...  up to 180 μ.s. single-photon storage duration, a record for this class of absorptive memory, equivalent to >30 km fiber transmission distance, preserving quantum entanglement between stored photon/ its telecom-wavelength pair... quantum repeaters, scalable global quantum internet"