Oxford experiment links quantum memories across two locations
オックスフォード大学の実験、離れた2か所の量子メモリーを接続科学・技術
- Country:
- 🇬🇧 United Kingdom
- Voice:
- 🇬🇧 Oliver
英語本文
Physicists at the University of Oxford in Britain built an experimental quantum network connecting two locations by optical fibres. Its four qubits, or units of quantum information, were encoded in four trapped atomic ions. Each location held one strontium ion and one calcium ion, with electromagnetic fields keeping these electrically charged atoms in place.
Each strontium ion emitted a photon. Combining and measuring the photons at a central station produced a detection pattern signalling entanglement: a shared quantum state that cannot be described independently for each particle. Local operations extended this entanglement to calcium ions, creating shared states involving three or four ions across both locations.
Calcium states were less sensitive to magnetic-field noise, preserving remote entanglement for about 10 seconds, against milliseconds for the network ions. Published in Physical Review Letters, this was a small laboratory network, not a general-purpose distributed computer. More complex network protocols, error correction, remote sensing and atomic-clock comparisons remain future research aims.