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Kilometre-long pulses of light have been stored for over one second in a 0.1 mm cloud of ultracold atoms – before being revived and sent on their way. This latest demonstration of light storage using electromagnetically induced transparency (EIT) is the first to break the second barrier – using ultracold atoms and has the added bonus of preserving the quantum state of the incoming pulse. The physicists in the US who carried out the experiment say that the work could play a key role in quantum information technology.

If a practical quantum computer is ever built, he says, it will have to make use of different kinds of quantum bits, perhaps atoms for storage and photons for transmission. So teleportation would be a natural way to connect these components, he says.

An international team of physicists has created the first system that can produce verifiably random numbers. The technique relies on the inherent uncertainties in quantum mechanics and future versions could help cryptographers to encode information more securely than ever before.

quantum cryptography, according to some engineers, is not without its faults. In a preprint submitted late last week to arXiv, Hoi-Kwong Lo and colleagues at the University of Toronto, Canada, claim to have hacked into a commercial quantum cryptography system by exploiting a certain practical “loophole”.