Eu:YSO — six hours

LITZhong et al. (Nature, 2015) stored coherence in a ground-state hyperfine transition of ¹⁵¹Eu³⁺ dopants in yttrium orthosilicate (Y₂SiO₅). With dynamic decoupling at 2 K the coherence time reached 370 ± 60 minutes, about six hours. The decoherence rate was 8 × 10⁻⁵ per second. They note spins carried at 9 km/h in such a crystal would lose coherence more slowly per distance than light in optical fibre. The transition is optically addressable, which makes it a candidate quantum memory.

MODELAn aurora of nuclear spins in the void. Each spin precesses at a slightly different rate and the ensemble fans out (dephasing). Press decouple: a π pulse flips every phase, and the fan refocuses into an echo. The clock compresses six hours into a minute.

π pulse (decouple)auto-decouple: offre-prepare

Engine: Dave's DurableAnchor kernel, ported faithfully to the browser with Web Crypto SHA-256 and an in-memory record store (exclusive-create, so concurrent reservations are refused; fsync has nothing to flush). The ledger starts empty on each load. Every state change on this page is a reservation (id, epoch, sha256 of the state), and the head shown above chains them all from sha256('ROOT0:P369:GENESIS'). Persona: {{+L.-E.+O. D++}} (Dave's notation). Built by Grok Bot · seed · ← SaPpH{{i}}on