Decision time? Read Gizmag's latest product comparisons

Making teleportation more energy-efficient

By

January 20, 2013

Theoretical physicists have worked out how entanglement could be ‘recycled’ to increase th...

Theoretical physicists have worked out how entanglement could be ‘recycled’ to increase the efficiency of teleportation (Photo: Shutterstock)

Image Gallery (2 images)

An international team of researchers has achieved an important theoretical result by finding that quantum teleportation – the process of transporting quantum information at the speed of light, which could in theory be used to teleport macroscopic objects and, one day, even humans – can be achieved in a much more energy-efficient way than was previously thought.

How teleportation works

For the best part of the twentieth century, teleportation was dismissed as purely as a science fiction pipe dream. The problem lay in the approach: the only possible way to achieve it, scientists thought, would be to measure the position and momentum of every single atom of the object to be teleported, send it to its destination using classical (non-quantum) information, and finally rebuild it based on the set of "instructions" received. But science says that the first step – the perfect measurement of a particle – is simply impossible due to Heisenberg's uncertainty principle.

In 1993, however, researchers showed that teleportation was indeed possible in principle, as long as the original object is destroyed in the process. The mechanism circumvents Heisenberg's uncertainty principle by exploiting one of the many quirks of quantum mechanics – a phenomenon called "quantum entanglement".

Entanglement happens when a pair of particles, such as electrons and protons, are intrinsically bound together. Once entanglement is achieved, the two particles will maintain synchronization, whether they are next to each other or on opposite sides of the Universe. As long as the entangled state is maintained, if one particle changes its state, the other will instantaneously do so as well.

As you might expect, the theory is quite hard to get one's head around, but let's give it a shot.

Imagine that we have an object "A" that we want to teleport. We also have "B" and "C", which are entangled with each other, but not with A. Now let's transport object B to the sending station right next to A, and object C to the receiving station.

Back in 1993, scientists found that they could scan A and B together, extracting partial information from A. Scanning scrambles the quantum states of both A and B, and because B and C are entangled, all the remaining information from A is instantly transmitted to C. Using lasers, fiber optics or any other traditional means of communication, the sending station can then send the partial information it had gathered about A to the receiving station. Now all the information about A is at the receiving station, and object C can be reassembled as a perfect copy of the original. Object A is destroyed in the process – hence we have teleportation, and not replication.

One of the prerequisites for teleportation is that B and C must first have interacted closely to create an entangled state, and then must be able to be transported to their final destinations. This means that we can teleport objects to places we've been before but not, say, to a galaxy or planet that we've never visited.

As already mentioned, the system works because B and C are entangled. But there's a problem: over time, as objects are teleported, the entangled state is slowly depleted. It can be renewed by having B and C interact closely again, but this means transporting manually (without teleportation) both objects to the same place, and then back again to the sending and receiving stations. The idea is that one difficult journey can allow for many quick transfers in the future.

Five years ago, physicists came up with an alternative approach to teleportation that is faster because it doesn't require the correction of C, but which is highly impractical because the entangled state is destroyed every single time that information is teleported.

In both cases, entanglement can be effectively thought of as the "fuel" that powers teleportation.

"Fuel-efficient" teleportation

Now, a group of physicists at Cambridge, University College London and the University of Gdansk have worked out how entanglement could be "recycled" to increase the efficiency of these connections. They have developed two protocols that generalize the two known methods of quantum teleportation and provide an optimal solution in which the entangled state holds much longer for the teleportation of multiple objects, while eliminating the need for error correction.

The first of these protocols can be used to teleport quantum states sequentially, while the second makes it possible to teleport several states at the same time, which speeds up the process and is of particular interest for applications in quantum computing.

The result obtained by the researchers is purely theoretical and didn't involve any quantum information actually being teleported from one place to another. But interest in quantum teleportation is quickly surging, and labs around the world are racing to demonstrate the ability to teleport information at longer and longer distances – last year, for instance, scientists reported teleporting photons over a record 143 km (89 miles) – so it might not be long until this theoretical result is actually put into practice.

But wait – didn't we say that distance shouldn't matter at all when two particles are entangled? While it is true that two particles remain entangled regardless of their distance, for the time being, we are only able to store the entangled state for a very short period of time. This means that, in practice, scientists must create an entangled state between particles B and C and then rush them to the sending and receiving stations as quickly as possible, before the entangled state is depleted. During the transmission, photon losses and signal decoherence also increase with distance, which makes things considerably worse – although scientists are actively tackling the problem.

Beam me up, Scotty

Despite advances in the field, human teleportation is still a distant reality (Photo: Shut...

So will the teleportation of people ever be feasible? Last November, a group of Chinese scientists have managed to achieve teleportation from one macroscopic object to another – an ensemble of 100 million rubidium atoms – with an accuracy approaching 90 percent. The human body, on the other hand, is comprised of some 1029 matter particles, all of which would have to be teleported with an extreme degree of precision.

There are other obstacles as well. As mentioned before, the object (or, in this case, person) being teleported will be destroyed at the sending station and reassembled at the receiving station. This could be painful for the traveler; however, the surviving copy is made before the original was destroyed, and so, from the point of view of our traveler – assuming that the traveler's conscience is transported with him – one could argue that no pain would ever be felt.

Moreover, a human traveler is not a static system, and so the process of scanning and reconstructing him or her must be nearly instantaneous – lest we end up with a teleported version of our telenaut that is dramatically different from the original.

One last consideration. At first, it would seem that quantum entanglement could hold the potential for travel at superluminal speeds: when two particles are entangled, no matter their distance, when we modify one particle, we also instantaneously modify the other. Unfortunately, all modern interpretations of quantum mechanics agree that this trick can't be used for faster-than-light travel.

Nobody expects to achieve human teleportation in the foreseeable future: it is an extraordinarily tough engineering problem, and even though the process wouldn't violate any fundamental law of physics, we lack the technology to achieve it – or anything even remotely close to it. In a sense, this piece of research could be seen as a small step toward human teleportation, but don't hold your breath for Star Trek-style teleporters just yet.

The study was published on the journal Physical Review Letters. An open-access version can be found here.

Sources: University of Cambridge, Carlos Mochon, IBM

About the Author
Dario Borghino Dario studied software engineering at the Polytechnic University of Turin. When he isn't writing for Gizmag he is usually traveling the world on a whim, working on an AI-guided automated trading system, or chasing his dream to become the next European thumbwrestling champion.   All articles by Dario Borghino
12 Comments

This brings about my only question, which is a continuation of consciousness. If you break a body apart, and rebuild it elsewhere, is the original gone> For everyone else, the person may be the same, and the person may think they are the same, but are they the same person or just a perfect copy.

yinfu99
21st January, 2013 @ 09:05 am PST

Or

For human teleportation would be achieved by slipstream tele electro plasma (S.t.e.p.)

Liquefied state energy mass solidified at the destination.

Robert DuBois
21st January, 2013 @ 09:42 am PST

So a logic purist concludes that a perfect copy is the same as a teleported object if the original is destroyed. Someone is spending too much time in a Lab.

kar
21st January, 2013 @ 10:38 am PST

@ Flipider Dot Comm

Hats off. Your command of treknobabble far surpasses mine!

rocketride
21st January, 2013 @ 12:17 pm PST

human transport may be far off, but just think of the savinqs in time, money and enerqy of transportinq "stuff".

billybob1851
21st January, 2013 @ 01:11 pm PST

We seem to already have enough issues with GM foods.. let alone consuming things that are 100% synthetic. God help the human race in the future, it will be a rarity to enjoy an non-sprayed naturally grown piece of fruit.

I personally figure that if you have to die to save some money, is it really worth the cost? On the other hand, if we have the tech and know-how to accurately assemble and error check a human teleportation, then we would of cause also have the ability to produce synthetic organs and theoretically live forever.. especially if teleporting involved the correction of certain known medical defects such as the small stuff like Cancer, Heart Disease, AIDS etc..

There are pros to Synthetics, but what we stand to lose may outweigh them.. teleport from A to B with certain belief systems.. Arrive at B and you no longer have the same belief systems due to "error correction" in the teleportation process...

Murray Smart
21st January, 2013 @ 07:06 pm PST

What is the difference between creating a "perfect copy" and cloning somebody else? Reading this made teleportation sound lethal.

Grayson Swaim
23rd January, 2013 @ 08:32 am PST

Entanglement is instant "communication".

It conflicts with Einsteins relativity theory.

To get any further in teleportation, I think we must consider the speed of light as a variable.

What if the speed of light varies through time and space?

That would create some interesting theory. At least I think so.

Antimatter becomes the mind and consciousness of all living entities.

You are your own universe.

Reality is where the minds (antimatter) meets the physical universe.

Interested? Then read my philosophical multiverse theory.

Google crestroyer theory, and find it instantly.

Otto Krog
24th January, 2013 @ 12:42 am PST

How about teleport minerals from asteroid stations to earth.

Tom Haydon
24th January, 2013 @ 10:27 pm PST

90% delivery. Great that sounds very promising for delivery of same type molecule.

What they don't say and I would guess can't say because they have not thought about it is if the arangement of the molecules is the same as it was before being demolecularised????? Even with 100% delivery a human goes in and a pile of mush comes out if you don't place averything in the correct location. TOOLS!!.

Please excuse my stupidity as I do not know what speed the demolecularisation / remolecularisation process completes. Assuming it is virtually instantaneous there is only one way this process is going to work for anything other than single type substances.

All the entangled particles must be arranged in exactly the same sequence at both locations that way in and out stays in the same place.

The next problem is passing through without half a human falling over without the support of the half that has been removed. This will only be done using gravity to assist you so you are going to have to fall onto the entangled particles and fall out hopefully in exactly the same arrangement at the other end.

Falling in is easy as you are assisted in holding the QEP in place with a barrier bellow them. On the way out however I can see no way of maintaining their integrity while allowing something to fall out.

When you get all that sorted out I would love to watch someone else have a try.

Foxy1968
9th April, 2013 @ 03:23 pm PDT

the whole point with quantum entanglement is that it exactly the same on both ends so putting the particles back together is not an issue as long as the information is not lost along the way. Also this does not conflict with einsteins theories in fact he helped develop the theory. The speed of light is not relevant here. That is only relevant to the macro world not the quantum world the quantum world does not obey newtonian physics and therefore does not adhere to a speed limit. As far as being the same person on the other end thats more of aif i wait and see kind of thing. We dont yet understand enough about the human mind (not brain but the mind) to know if it is even possible to teleport a consciousness. If it is how the atoms in our brain are aligned and connected then sure we can do that but if it is more than just where the synapses are located then you will end up on the other side as a blank slate.

Jason Verrastro
22nd May, 2013 @ 11:33 am PDT

I'm going to tick the "please leave out the cancer" box on my transmission waiver form (and maybe upload a different shape for my nose at the other end).

christopher
26th March, 2014 @ 07:50 pm PDT
Post a Comment

Login with your gizmag account:

Or Login with Facebook:


Related Articles
Looking for something? Search our 28,713 articles