Telecommunications

High-fidelity, long-distance teleportation paves way for quantum internet

High-fidelity, long-distance t...
A new quantum internet could be built using off-the-shelf components and existing infrastructure
A new quantum internet could be built using off-the-shelf components and existing infrastructure
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A new quantum internet could be built using off-the-shelf components and existing infrastructure
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A new quantum internet could be built using off-the-shelf components and existing infrastructure

A quantum internet would be much faster and more secure than the one you’re using right this second – and now such a network may be one step closer to reality. Scientists have used quantum teleportation to send information over long distances, with a higher fidelity than ever before.

Quantum entanglement is a strange phenomenon that sounds like science fiction to our classical-physics-focused minds. Basically, two or more particles can become so entwined that changing the state of one instantly changes that of its partners – no matter how far apart they are.

This mechanism – which Einstein himself dubbed “spooky” – can be tapped into to create quantum networks. Pairs of photons can be entangled and separated, allowing data to be “teleported” between them over long distances. As a bonus, these networks could be more secure, since any hackers would garble the data just by trying to read it.

Now, researchers at Fermilab, AT&T, Caltech, Harvard, NASA JPL and the University of Calgary have demonstrated sustained, very accurate quantum teleportation over long distances. The team sent information over 44 km (27 miles) with fidelity of over 90 percent – an accuracy record for this distance.

To do so, the team added a third “node” in the middle, between the sender and receiver. To get information from A to B, both parties first send a photon to C. The receiver, B, sends one member of an entangled pair and keeps the other. When A and B’s photons meet at C, they are then entangled, so that the information from A’s photon is transferred to both of B’s photons – the one it sent and the one it kept – thanks to the quantum entanglement link. In effect, it’s basically the same as teleporting information from A to B.

It’s not the longest distance quantum teleportation has been achieved. In 2015 information was teleported through optical fibers over 100 km (62 miles), and in 2017 Chinese scientists smashed the record by effectively teleporting data over 1,200 km (746 miles) using a satellite as the midpoint.

But the new experiments mark a breakthrough in fidelity over long distance. The 100-km record, for instance, managed about 80 percent accuracy, so 90 percent is an impressive improvement. The team also says that the experimental setup involved mostly off-the-shelf components, meaning a future quantum internet should be able to be built using existing infrastructure.

The research was published in the journal PRX Quantum.

Source: Fermilab, Caltech

9 comments
9 comments
FB36
IMHO it is absolutely essential today that government law enforcement needs to be able to access internet communication content, since most crime is done using internet today! (& general public is not obsessed w/ privacy & like to help government law enforcement; quite unlike some people think/claim!)

Also using quantum encryption would not really prevent any common security problems, like hackers or ransomware/malware, since they are never done by intercepting internet traffic in the middle!

But a quantum internet still could be useful as a secondary internet to be used only by government(s) & militaries! (Whose internet communication really needs to be protected against intercepting in the middle!)
piperTom
The actual Einstein quote is “I cannot seriously believe in [quantum mechanics] because the theory cannot be reconciled with the idea that physics should represent a reality in time and space, free from spooky action at a distance”. translated from German in a letter to Max Born in 1947). If Einstein err'd it was in arguing against the collapse of the wave function based on it being simultaneous in all frames of reference. It's an error because the collapse of the wave function conveys no information (nor any energy) and thus is NOT a violation of relativity.
robertswww
We need a modified version of this technology using entangled radio waves to build a long-range Quantum TX/RX radio... Imagine near instantaneous communications with our deep space satellites, or instantaneous communication with rovers and/or astronauts on mars.

Build a transmitter and receiver that utilize quantum entanglement of the radio waves and then when you transmit a message, it will instantaneously be received at the other end.
Kpar
This is why the SETI program is a dead end. Watching for radio signals in space is kind of pointless, if another civilization reached our level of understanding, they will be using quantum entanglement for communication, not radio waves.

Ans we're just at the beginning of this "spooky" stuff...
christopher
The "eavesdropping resistance" claims are looking a whole lot more sketchy now - since it's "C" which mediates the information exchange, it's perfectly placed to keep its own copy in the process simply by using different hardware; plus this opens the door to MitM on other pure A-B communications by inserting the same "C bug" into those too...
ScienceFan
So what was the data rate? Was it random unknown states that were discovered at both ends? And how fast did the information if there was any actually travel?
anthony88
Is this faster than light speed?
ljaques
Anthony88 had the ultimate question: Is this FTL comms?
Karmudjun
Thanks for the comments, I never thought of Einstein as someone to describe any phenomena as "spooky". Hope to see quantum internet in my lifetime. But it is nowhere close to teleportation of matter - no "beam me up scotty" with these breakthroughs.