Quantum computers' connection distance increased from a few km to 2,000 km by increasing coherence times, for global-scale quantum internet

https://www.eurekalert.org/news-releases/1104968

"entangling atoms through fiber cable... longer quantum coherence time enables greater distance... raised coherence times of individual erbium atoms from 0.1 to >10 ms... scalable Molecular-Beam Epitaxy: spray thin layers, like 3D printing, assembling rare-earth doped crystals atom by atom... superb quality/ purity, greatly increasing quantum coherence... future: validate these theoretical distances, first by simulating a 1,000 km link in the lab using spooled cable between 2 (later, 3) separate dilution refrigerators"