## Don’t Tell Bones: Are We One Step Closer to “Beaming Up?”

by Jason Major

It’s a crazy way to travel, spreading a man’s molecules all over the Universe…

While we’re still a very long way off from instantly transporting from ship to planet à la Star Trek, scientists are still relentlessly working on the type of quantum technologies that could one day make this sci-fi staple a possibility. Just recently, researchers at the University of Cambridge in the UK have reported ways to simplify the instantaneous transmission of quantum information using less “entanglement,” thereby making the process more efficient — as well as less error-prone.

(Because nobody wants a transporter mishap.)

In a paper titled Generalized teleportation and entanglement recycling, Cambridge researchers Sergii Strelchuk, Michal Horodecki and Jonathan Oppenheim investigate a couple of previously-developed protocols for quantum teleportation.

“Teleportation lies at the very heart of quantum information theory, being the pivotal primitive in a variety of tasks. Teleportation protocols are a way of sending an unknown quantum state from one party to another using a resource in the form of an entangled state shared between two parties, Alice and Bob, in advance. First, Alice performs a measurement on the state she wants to teleport and her part of the resource state, then she communicates the classical information to Bob. He applies the unitary operation conditioned on that information to obtain the teleported state.” (Strelchuk et al.)

In order for the teleportation to work, the process relies on *entanglement* — the remote connection between particles or individual bits of information regardless of the physical space separating them. This was what Einstein referred to as “spooky action at a distance.” But getting particles or information packets entangled is no simple task.

“Teleportation crucially depends on entanglement, which can be thought as a ‘fuel’ powering it,” Strelchuk said in an article on ABC Science. “This fuel… is hard to generate, store and replenish. Finding a way to use it sparingly, or, ideally, recycling it, makes teleportation potentially more usable.”

**Read: Beam Me Up, Obama: Conspiracy Theory Claims President Teleported to Mars**

Considering the sheer amount of information that makes up the also-difficult-to-determine state of a single object (in the case of a human, even simplistically speaking, about 10^28 kilobytes worth of data) you’re obviously going to want to keep the amount of entanglement fuel needed at a minimum.

Of course, we’re not saying we *can* teleport red-shirted security officers anywhere yet. But *if.*

Still, with a more efficient method to reduce — and even recycle — entanglement, Strelchuk and his team are bringing us a little closer to making quantum computing a reality. And it may very well take the power of a quantum computer to even make the physical teleportation of large-scale objects possible… once the technology becomes available.

“We are very excited to show that recycling works in theory, and hope that it will find future applications in areas such as quantum computation,” said Strelchuk. “Building a quantum computer is one of the great challenges of modern physics, and it is hoped that the new teleportation protocol will lead to advances in this area.”

(I’m sure Dr. McCoy would still remain skeptical.)

You can find the team’s full paper here (chock full of maths!) and read the article on ABC Science by Stephen Pincock here.

*Transporter room image from TOS “Obsession” episode. © 2013 CBS Studios Inc. All Rights Reserved.*

entanglement, Physics, quantum, Star Trek, teleportation, transporter, University of Cambridge

We just need to invent Heisenberg compensators. Teleportation solved. 😉

I know exactly how the Heisenberg compensators worked – very well!

Well, I’m not sure. 🙂

and bring back Scotty…….

The guy next to Kirk didn’t make it back did he?

he is a redshirt …. it kinda is entangled information that he won’t make it back.

True, often resulting in Kirk inadvertently receiving a double dose of Teleportation, hence the Kirk of the future gaining so many pounds…:-(

When did this become the Huffington Post? This is a fascinating and important subject that you have trivialized by insisting on pretending it’s a step toward macroscopic teleportation. I expect this from what passes for science reporting in the mainstream media, but I expect better from UT.

We have to learn to walk before we can run, and we have to be able to run before we can go warp speed. Science fiction’s most important contribution is the inspiration of actual science and this is no different. I’m just making the inevitable connection; may the research continue!

Way to completely ignore the point of my post. This isn’t science fiction, it’s real science with interesting and important potential real-world applications. And, your cliches aside, transportation of macroscopic objects just isn’t one of them. You may consider this kind of sensationalism and distortion of the science “inevitable,” but that doesn’t remove your responsibility for engaging in it.

And if you think your article (and its title) doesn’t give people the mistaken impression that this technology has the potential for macroscopic teleportation, just read the comments below.

“Of course, we’re not saying we can teleport red-shirted security officers anywhere yet. But if.”

You must have missed that part. That’s ok, if you want to put a cap on imagination and speculation, go right ahead. But don’t complain if some people push past it. (It’s in our nature.) If folks like a sprinkle of “sensationalism” to get them excited about science, then I’m all for it. Engage indeed!

I’ve noticed Universe Today being referenced over on io9.com. I wonder if there’s connections behind the scenes.

Nope, no connection, we’re just friends.

From what I read this might not be a good teleportation technique. It implies reading your code, destroying you and then reassembling you from different atoms. Just the information is teleported not the physical bit. This is what I understood anyway. So if I’m wrong please correct me.

Totally agree – this the fictional engineering premise that underlies STNG’s linking of the holodeck and transporter technologies.

Considering all the doom and gloom that physicists are spewing about warping, and how it will be utterly-destructive to that try it, perhaps in the far future teleportation may be the key to interstellar travel! (Would be a ‘quick’ way to travel, no? :P)

But that said, I don’t like the sound of being deatomized(Is that even a word?) in one place, and reassembled in another – it would defeat the purpose of being ‘alive’, and essentially the “You” that was having their atomic-structure scanned and destroyed would be instantly KILLED. Only a copy would exist, and they too wouldn’t know the difference.

Yes to Teleportation, no to THIS kind of Teleportation, Pretty Please! 🙂

Teleportation goes no faster than the universal speed limit.

So again, this is not very affordable on astronomical scales, it will be the same cost as all messages.

I’m with Douglas Adams. If they have to take me apart to get there, I don’t want to go.

Larry Niven’s essay ‘The Theory and Practice of Teleportation’ would eb a relevant read here.

No, they didn’t. Or if they did, they were wrong.

Quantum mechanics obeys relativity, which is what Bell experiments tests. (And to the lowest uncertainty of any physics measurement, I note, typically over 20 sigma.) Causality is preserved, “she communicates the classical information to Bob” with the universal speed limit in place.

What Bell experiments show is effects on quantum correlations, what happens when the classical information can be applied to interpret the outcome of the experiments. The correlations can change at any time, but this does not affect the quantum (wavefunction or field) information that is transmitted, only the interpretation.

So what use is teleportation? Well, it could cut down on the energy used for transport, by recreating an object from local matter.

But it is most often overkill. We don’t need copies of a system that was. (“Was” since “no cloning” tells us that the original system is now affected so that the copy proceeds causally in the new environment, but the entangled original is changed irretrievably.)

For example, neurons would work similarly even if the molecules were not in the exact same quantum states after teleporting. And the environment has changed anyway, so exact quantum states are superfluous.

I would guess 3D printing technology is the better choice in most cases.

There is some confusion here about the meaning of teleportation. As this bolg entry puts it, this very much depends upon entanglement. A state entanglement may be arrived at through the decay of a spin = 0 particle that decays into two spin ½ particles. The two spin ½ particles exist in a wave function

|?> = (1/sqrt{2})(|+>|-> + e^{i?}|->|+>

Here the basis of states |+> and |-> correspond to spin up and down along some direction one intends to make a measurement. The e^{i?} is a phase term. The ordering of the |+> and |-> basis elements corresponds to particle #s 1 and 2. If you then have the two particle travel to two different regions of space, the if observers #1 and #2 orient their measurement apparatus (Stern-Gerlach apparatus) in the same direction then if observer #1 measures spin up/down then observer #2 gets spin down/up. This is an entangled state.

Now suppose that our two observers have these two pairs of states, called an Einstein-Podolsky-Rosen (EPR) pair, and locate themselves in two different regions of space. Observer 1 decides that he want now to entangle another state to his state. The possible state in general are

|+>|-> – |->|+>

|+>|-> + |->|+>

|+>|+> – |->|->

|+>|+> – |->|->

and orthogonal states, called Bell states. I call these 1, 2, 3, 4. Observer 1 makes his measurement and entangles this other state to it. Observer 1 then sends to observer 2 this number, and this is a classical signal. She then takes this number and performs one of the four operations on her state:

1: leave alone

2: rotate ?around the z axis

3: rotate ?around the x axis

4: rotate ?around the y axis.

The state configuration observer 2 finds is the teleportated state. These rotations are formally done with the Hadamard matrix.

There are then a couple of things that are to be noted. Observer 2 will not be able to find the teleportated state without the classical signal. If she tries to measure it she will just get one of the outcomes corresponding to the Bell states. So this teleportation is not a way to communicate information faster than light. The other is that the classical communications is 2 bits and there is the demolition of the original entangled state. As a result this process is not done for “free.”

There is no cloning of the state. Observer 1 loses his state. States can’t be cloned or copied for the following simple reason. Suppose I have a state |?> = a|+> + b|->, where a and b are normalization numbers. So now I duplicate it and get

|?> — > |?>|?> = (a|+> + b|->)( a|+> + b|->)

= a^2|+>|+> + b^2|->|-> + ab(|+>|-> + |->|+>)

However, if this operation is unitary it should equivalently work on the basis elements |+> and |-> alone

|?> — > a^2|+>|+> + b^2|->|->

and the two are not equal. So this is not a process that can be performed by the unitary processes or evolution of quantum mechanics.

As a practical matter it is not likely that we will get Star Trek transporters. You can only transport quantum states, and large objects are thermal distributions that are hard to “make” into quantum coherent states. As the number of degrees of freedom becomes large quantum systems tend to behave more as classical or thermal systems.

LC

So the No-cloning theorem holds after all?

It’s well above my pay grade, but there are a few papers out there that seem prepared to give that theorem a beating, e.g. Quantum Cloning Machines and the Applications, Local cloning of entangled states and Quantum Cloning of Continuous Variable Entangled States.

I am a bit aware of this research. The no-cloning theorem is pretty solid. However, the question arises as to whether a partial cloning can be performed. The preparation of identical pure states is a sort of cloning, but it requires nonunitary processes. The matter here is whether there are bounds on the cloning theorem and what measure of nonunitarity is required to duplicate states.

LC

How much information does it take to transport water or even easier an element. Transporting material would be the obvious first step. Plus no lawsuit when grandma dosn’t make it.