Researchers Achieve Quantum Entanglement Over Record Distance
Quick Look
Researchers successfully achieved quantum entanglement between two quantum memory units 420km apart using an optical fibre link, exceeding previous limits.
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Why It Matters
Scientists previously succeeded in entangling light particles across space and optical fibre, but adding quantum memory increases complexity.
According to a paper published by the peer-reviewed journal Physical Review Letters on August 11, the distance was more than four times previous demonstrations and exceeded the threshold at which direct transmission encounters fundamental physical limits.
The researchers used two quantum memory units, each consisting of laser-cooled clouds of rubidium atoms, 420km apart and connected by an optical fibre link.
The aim was to achieve entanglement – the phenomenon in which two or more particles – often photons – become inextricably linked, sharing a joint quantum state regardless of the physical distance between them.
While scientists have previously succeeded in entangling light particles across vast stretches of empty space and through optical fibre, introducing quantum memory into the equation makes the process more complex.
Open Questions
- What specific applications will this technology enable?
- How can the distance be further scaled?
