Physics

Quantum teleportation takes on a new dimension in new experiments

An artist's rendition of quantum teleportation involving three dimensional states
An artist's rendition of quantum teleportation involving three dimensional states
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An artist's rendition of quantum teleportation involving three dimensional states
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An artist's rendition of quantum teleportation involving three dimensional states

Unlike regular computers where data is stored in binary bits as 0 or 1, the “qubits” in quantum computers can exist as both at the same time. Stranger still, this information can be effectively “teleported” over any distance. Now, scientists from Austria and China have managed to create photons that exist as 0,1 and 2 simultaneously, and teleported these complex quantum states.

Quantum computers are poised to leave traditional computers and even supercomputers in the dust, and they owe their exponential increase in power to the fact that they go beyond binary. One “bit” of information isn’t limited to a 0 or a 1 – it can be either or both at the same time, much like Schrödinger’s infamous cat.

In theory, adding extra states boosts the power even more: throw in a 2, for example, and the range of possible states goes up exponentially. One qubit can be any individual value, or any pairing of two, or all three at once.

And now these theoretical higher-dimension quantum states have not only been demonstrated in lab experiments, but teleported as well. The team includes scientists from the Austrian Academy of Sciences, the University of Vienna, and the University of Science and Technology of China.

The team based its experiments on a long-standing favorite called the Bell test. In this, two photons are emitted in different directions at the same time, and when a certain property of one is manipulated and measured, the other usually ends up being the same. That information appears to be “teleported” to the second photon, no matter how far apart they are.

For the new study, the researchers adapted the classic experiment to teleport a three-level state, which they call a “qutrit.” The quantum state in this case is which of three optical fibers a photon is traveling through – remembering of course, that quantum physics allows a single photon to be in any or all three of the fibers at once.

The team used a multiport beam splitter to direct the photons, and then manipulated their states using auxiliary photons. By carefully controlling the interference patterns of these photons, the team was able to successfully teleport that quantum information to another photon, even though the two photons never interacted physically.

This experiment shows that quantum teleportation can not only be done in three dimensions, but theoretically it can be done in any number of dimensions.

This study is a step towards harnessing quantum mechanics for better electronics. In the not-too-distant future, a quantum internet could connect quantum computers together to send data incredibly fast through quantum teleportation.

The research was published in the journal Physical Review Letters.

Source: University of Vienna

9 comments
guzmanchinky
Very exciting times, but this quantum stuff messes with my head.
Eric Wilson
If i'm understanding this right, they aren't actually teleporting "information". Normally with entangled particles you'd decide what dimension to measure, and the states of the two particles in that dimension would be related. As a total layman (which probably means I'm wrong) the only way I can think of to send "information" via entanglement might be via which dimension you choose to measure? If you measure about dimension "X" with possible values (a or b), if particle 1 = a , then you know particle 2 = b. Maybe you could say at 12:00 we'll measure particle 1 against dimension "Y" if we want to say "hi" and dimension "X" if we want to say "bye" . At 12:01 if you'd measure particle 2. If you can't measure about the "Y" dimension you can conclude that the waveform collapsed on the "X" dimension and therefore that particle 1 was measured along "X" and your plan says that means "hi"
rederje
read the original open papers : Experimental multi-level quantum teleportation https://arxiv.org/pdf/1904.12249.pdf Quantum teleportation in high dimensions https://arxiv.org/ftp/arxiv/papers/1906/1906.09697.pdf Quite complex in quantum mathematics, but simply the apparent collapse of the wave-function occurs all over our universe in a measurement over 13.6 billions light years, at a nearly infinite speed that remains to be measured, witout teleporting real information ! Equivalently, all observers remain in the same world or universe when our big universe splits into many parallel universes in a quite complex measurement, without collapse !! The entangled quantum state is the same over all of our universe and thus a measurement at one point on a delocalized entangled quantum state looks teleported identically to all others measurements far away.
drdoug
Interesting article but you must know we transmit and "teleport" this type of data every day in 0's and 1"s. What we hope is that in some, possibly new protocol manner, that we will be able to transmit objects and reassemble them perfectly. That is what many folks are working on. Not sure if this is truly at all possible because of the very basic understanding we hold in assembly and disassembly but it keeps us all excited about such discovery which gets us closer. Thank you...
Norm.Rhett
"... send data incredibly fast through quantum teleportation." sounds like superluminal communication, which is considered to be impossible.
Jerome Morley Larson Sr eAIA
Split light travels away from itself at the speed of ... um.... light — at that speed no time exists relatively, so of course both halves or thirds or whatever will instantly have the same properties at the same time regardless of the distance traveled apart — so what’s the big deal?
sidmehta
Aren't there any theories explaining why information can be sent instantly with zero time delay through huge distances?
Roddy Redstate
This is probably the clearest article I've ever read about qubits and quantum computers. As a non-scientist, I find it hard to find articles on this topic that I can decipher. Mr. Irving made me think I could actually grasp these concepts -- no small feat! Thank you for your efforts in writing an article accessible to almost anyone about a topic accessible to so few.
f8lee
@NormRhett - I believe the big deal about quantum entanglement (at least as I am given to understand it) is that the paired particles, like Schrödinger’s cat, maintain all possible states until either is observed. (or in the case of the cat, is both alive and dead simultaneously). Quantum theory states that it is not a matter of us mere humans not "knowing" the state the particle is in; the particle literally is in all states until an observation is made - at which point the wave collapses and the spin (or whatever) is "locked in". Again, the spin (or whatever) simply did not exist prior to the observation - that's the crazy quantum theory stuff there - it only occurs when the observation is made. So when two particles move away at light speed and some time later (when they are, obviously, further apart that photons can travel between them) one of them is observed and its wave form collapses, the other particle's does the exact same thing simultaneously. Sounds maddening, but that's why Einstein called it "spooky action at a distance"