Category: Weird ‘n’ spooky
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Graphene quantum computers could be built with today’s technology
Is there anything graphene cannot do? The great graphene gold rush continues today with the news that graphene nanoribbon could be the key ingredient of the next generation of quantum computers. The trick with quantum computing is to use qubit-carrying particles that are easy to manipulate so that their quibits can be written and read,…
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Spooky action at a distance gets spookier
Take a pair of entangled photons and perform a measurement on one of them. According to the strange laws of quantum mechanics, this measurement immediately influences the state of the second photon, no matter how far apart they are. Einstein bridled at the possibility that an instantaneous influence could take place. He called it spooky…
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Schroedinger-like PageRank wave equation could revolutionise web rankings
The PageRank algorithm that first set Google on a path to glory measures the importance of a page in the world wide web. It’s fair to say that an entire field of study has grown up around the analysis of its behaviour. That field looks set for a shake up following the publication today of…
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Creating random numbers the quantum way
The stream of high quality papers continues from the lab of Andrew Shields at Toshiba Research in Cambridge, UK. Today, his team unveils a new type of quantum random number generator and a fine looking machine it appears to be. Here’s the idea. Create a stream of single photons are emitted at random intervals that…
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Quantum communication: when 0 + 0 is not equal to 0
One of the lesser known cornerstones of modern physics is Claude Shannon’s mathematical theory of communication which he published in 1948 while juggling and unicycling his way around Bell Labs. Shannon’s theory concerns how a message created at one point in space can be reproduced at another point in space. He calls the conduit for…
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Can entanglement exist in biological systems?
Can entanglement exist in biological systems? The usual argument against is that physicists have to work hard to produce entanglement in the carefully controlled conditions that exist in the lab. So it’s hardly likely that entanglement will ever be found in systems that are warm, wet and messy, like human bodies for instance. But Sandu…
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How to build a quantum internet
You could be forgiven for thinking that a quantum version of the internet is a couple of-afternoons-in-the-lab away from being plumbed into your living room. In reality, there are significant engineering challenges to overcome, says Jeff Kimble from the California Institute of Technology in Pasadena and one of the leading thinkers on the links between…
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The popcorn experiment and spooky action-at-a-distance
In 1964, John Bell became fascinated by the EPR paradox, an idea that Einstein had dreamt up to highlight what he saw as a major flaw in quantum mechanics. The paradox (called EPR after Einstein and his mates Boris Podolsky and Nathan Rosen) is a thought experiment involving two particles that share the same quantum…
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How to build a quantum eavesdropper
In the cat and mouse game of preparing and eavesdropping on secret messages, quantum encryption trumps all. At least, that’s what we’ve been told. The truth is a little more complex. Quantum key distribution, the quantum technique by which a classical encryption key can be transferred, is perfectly secure in theory. In practice, there are…
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Testing “spooky action-at-a-distance” on the International Space Station
Entanglement is the strange and beautiful property of certain quantum particles to become so deeply linked that they share the same existence. According to quantum theory, that link should be maintained whatever the distance between the particles, whether the width of an atom or the diameter of the universe. This led Einstein to claim that…