Sunday, May 27, 2012

Chinese Researchers Set New Distance Record For "Teleporting" Qubits

One of the most astonishing and confusing properties of the quantum world is the phenomena of quantum entanglement. Through this effect, it's possible for two individual particles to become linked to one another and act as single system, regardless of the distance between them.

Say, for instance, you managed to entangle a couple of particles, A and B. Even if particle A were residing quietly inside an accelerator here on Earth, while particle B was busy floating along through space on the other side of the galaxy, this entangled pair would still act as a single system. If one were to then try and observe particle A - thus causing a shift in it's quantum state through the mere act of observation, and the joy of  the uncertainty principal, quantum superposition, and all that - particle B, would instantaneously adopt the same quantum state.

Now, I'm not going to pretend to understand exactly how quantum entanglement manages to happen in the first place, or how scientists manage to deliberately produce the effect for experimentation, because, I don't- in my defense, neither does anyone else. But the phenomena of quantum entanglement is one that's been known to, and studied by, quantum physicists, for quite some time. And while it's easy to imagine a whole host of spectacular Sci-fi applications for the effect (some of which might also become a reality someday), currently, one of the most promising, real world application for entanglement, is in the field of data transfer, processing, and communications.

Enter, the Qubit. Which is the quantum analog to the the digital bit.

Now then, if I've done a fair job of explaining the concept of entanglement to you, you'll understand why the word teleporting appears in quotation marks in the title of this entry. Because when a group of scientists from China recently managed to set a new record for quantum "teleportation" by successfully transferring information between 1100 photons, across 97 km of free-space, they didn't actually teleport anything. Rather, they managed to successfully entangle and effect one group of particles, by manipulating another, across a previously unachievable distance. In other words, they were able to transfer data (qubits), from one place to another, without actually transferring anything at all. Which is kind of what makes Quantum entanglement such an attractive means of communication and data transfer in the first place. Since there's literally nothing to intercept, eaves dropping on this form of quantum communication,  would be nearly impossible. I say nearly, because, I can easily imagine some clever person finding a way to entangle a set of particles of their own, in order to intercept transmissions. But that too is just my own bit of speculative science fiction, at this point.

One of the (many) current problems and limitations of this particular method of quantum transfer, and why this groups achievement is a significant one - aside from just being cool as hell- is that entangling particles is understandably difficult. So the entanglements currently being created, are easily broken and interfered with. Which is why the previous record for such a transfer, which was also set by a group from China, in 2010, was just 16 km,.Which still seems an impressive feat, by my standards. But if the results of experiments like these can be reproduced, and the entanglements themselves can be made more stable. I think communications through quantum "telepotation", might actually be a reality, someday. Though certainly not anytime soon.

As for actual the actual teleportation of complex matter, which is what we all think of when we read the word... Sorry, but I still don't see it happening.

But that's a discussion for a different day.


VIA: Wired Science -And-

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