Integrated spin-wave quantum memory synchronized to connect multiple short-distance into long-distance entanglement

https://www.eurekalert.org/news-releases/1069417

"overcomes transmission photon loss, enabling construction of large-scale quantum networks... rare-earth ion doped crystals... spin-wave storage stores photons into spin-wave excitation in ground states, enabling on-demand retrieval with storage time extended to spin coherence lifetime... separates single-photon-level signal from noise induced by strong control pulses using direct femtosecond-laser writing fabricating circularly-symmetric waveguide in Eu:YSO crystal, enabling polarization-based noise filtering"