Beam Me Up... maybe?

[LadyTevar]

Scientists teleport two different objects

LONDON, England (Reuters) -- Beaming people in "Star Trek" fashion is still in the realms of science fiction, but physicists in Denmark have teleported information from light to matter bringing quantum communication and computing closer to reality.

Until now scientists have teleported similar objects such as light or single atoms over short distances from one spot to another in a split second.

But Professor Eugene Polzik and his team at the Niels Bohr Institute at Copenhagen University in Denmark have made a breakthrough by using both light and matter.

"It is one step further because for the first time it involves teleportation between light and matter, two different objects. One is the carrier of information and the other one is the storage medium," Polzik explained in an interview on Wednesday.

The experiment involved for the first time a macroscopic atomic object containing thousands of billions of atoms. They also teleported the information a distance of half a meter but believe it can be extended further.

"Teleportation between two single atoms had been done two years ago by two teams, but this was done at a distance of a fraction of a millimeter," Polzik, of the Danish National Research Foundation Center for Quantum Optics, explained.

"Our method allows teleportation to be taken over longer distances because it involves light as the carrier of entanglement," he added.

Quantum entanglement involves entwining two or more particles without physical contact.

Although teleportation is associated with the science-fiction series "Star Trek," no one is likely to be beamed anywhere soon.

But the achievement of Polzik's team, in collaboration with the theorist Ignacio Cirac of the Max Planck Institute for Quantum Optics in Garching, Germany, marks an advancement in the field of quantum information and computers, which could transmit and process information in a way that was impossible before.

"It is really about teleporting information from one site to another site. Quantum information is different from classical information in the sense that it cannot be measured. It has much higher information capacity and it cannot be eavesdropped on. The transmission of quantum information can be made unconditionally secure," said Polzik whose research is reported in the journal Nature.

Quantum computing requires manipulation of information contained in the quantum states, which include physical properties such as energy, motion and magnetic field, of the atoms.

"Creating entanglement is a very important step, but there are two more steps at least to perform teleportation. We have succeeded in making all three steps -- that is entanglement, quantum measurement and quantum feedback," he added.

[GrandMasterTerwynn]

It is, as they've pointed out, a fantastic development for quantum computing, since you can do your computation using qubit atoms, and transmit the output to other computers, or to the outside world, via their entangled photons. What it isn't,though, is a step towards Star Trek-style transporters, and will never be so. Spookily fast computers, yes, "Beam me up, Scotty", no.

It tends to annoy me whenever news writers associate quantum teleportation with sci-fantasy people-teleporters, since that's not the intended end-result of such experiments at all.

A better article regarding the implications of this can be had here

Spooky steps to a quantum network

* 18:00 04 October 2006
* From New Scientist Print Edition. Subscribe and get 4 free issues
* Zeeya Merali

Even if quantum computers can be made to work, there will still be two big obstacles preventing quantum networks becoming a reality. First, quantum bits, or qubits, stored in matter will have to be transferred to photons to be transmitted over long distances. Secondly, errors that creep in during transmission have to be corrected. Two unrelated studies have now shown how to clear these hurdles.

Both studies use quantum entanglement, a spooky property that links particles however far apart they are. Measuring a quantum property on one particle immediately affects the other, and this effect can be used to “teleport” information between pairs of entangled particles.

To make quantum networks possible, qubits need to be held in atoms or ions, processed, and then transformed into qubits of light for transmission between computers, says Todd Brun of the University of Southern California, Los Angeles. One way to do this, he says, is to teleport the state between a photon and an atom.

Until now, quantum teleportation has only been done between similar objects – from light to light or matter to matter – but Eugene Polzik at the University of Copenhagen in Denmark and his colleagues have taken the first steps towards doing what Brun suggests.

They entangled photons with caesium atoms, transmitted the light and then teleported properties of the photons on to equivalent properties in the caesium atoms (Nature, vol 443, p 557). The information only travelled half a metre, but that distance can be increased, Polzik says. “Potentially, the only limit is how far light can travel without the signal becoming degraded,” he says.

That raises the second problem: “Quantum states are fragile and easily get distorted during transmission,” Polzik says. Quantum systems are prone to two types of errors: qubits can flip between values of 0 and 1, or they can change phase.

Trying to figure out which kind of error has occurred is difficult, because of Heisenberg’s uncertainty principle. “When you try to measure one type of error you can end up creating the other type of error,” says Brun. “You do more harm than good.”

Now Brun’s team has devised a way out. The solution is to first create several entangled pairs of particles and share them between the transmitter and receiver before any information is sent.

The transmitter then sends its entangled particles along with the quantum information. The team has shown, in theory, that when the receiver combines these particles with its entangled twins, it can detect both types of quantum error (Science, DOI: 10.1126/science.1131563).

Polzik is impressed. “Quantum teleportation between light and matter can be dramatically enhanced with the use of such efficient quantum error correction codes,” he says.

Still. Very cool, this is.

[Burak Gazan]

It tends to annoy me whenever news writers associate quantum teleportation with sci-fantasy people-teleporters, since that's not the intended end-result of such experiments at all.

It's likely the Voyager Disease (tm) where every other week, something had to be involved with the quantum flux inducer framistan, or whatever similarly bullshit-based treknobabble they spewed out trickling down into the minds of these writers as "science"

From a computing standpoint though, as you say, very cool

[Admiral Valdemar]

Yeah, Terwynn voices my interest and qualms. So long as we have relativity, too, you will never get your FTL teleportation device either.

[LadyTevar]

Yeah, Terwynn voices my interest and qualms. So long as we have relativity, too, you will never get your FTL teleportation device either.

Hey, we can dream, can't we?

[Admiral Valdemar]

Humbug.

[LadyTevar]

Humbug.

*SMOOOCHIES*

Anyway... this is still going to be a ways off before production of a quantum computer PC. Still.. the thought of a computer that could run WoW without lagging or slowdown.

[Admiral Valdemar]

Maybe it'd even run Lock-On: Modern Air Combat at full graphical settings. Maybe.

[Ariphaos]

*SMOOOCHIES*

Anyway... this is still going to be a ways off before production of a quantum computer PC. Still.. the thought of a computer that could run WoW without lagging or slowdown.

Quantum Computing will not increase the amount of transferrable information. A quantum computer merely has the ability to analyze a number of states at the same time, and try to give the correct answer with high probability. If you can test it, you're golden.

Unfortunately only a few uses for this sort of thing are known. Quantum simulations (duh), integer factorization and discrete logarithms (the crypto thing everyone talks about), and database searches. Other algorithms may be out there now or waiting to be discovered, but ultimately, QC is still limited by the speed of light, and thus will not fix your lag.

The other fact of the matter is that while transistor-based computing seems to grow exponentially, quantum computing seems to develop at an inverse-exponential rate.