Scientists Explore Underwater Quantum Links For Submarines (ieee.org) 12
An anonymous reader quotes a report from IEEE Spectrum: Underwater quantum links are possible across 30 meters (100 feet) of turbulent water, scientists have shown. Such findings could help to one day secure quantum communications for submarines. [...] In the new study, researchers experimented with quantum communications in a "flume tank," a water tank in which scientists can generate waves to mimic the ocean. They also tried two different strategies for quantum communications -- one involving just the polarization of the light, and the other incorporating the polarization and the orbital angular momentum of the signals -- to analyze how quantum communication protocols might differ in maximum distances and data transfer rates.
The researchers achieved quantum communication at up to 72 kilobits per second across up to 30 meters of turbulent water, the longest distance yet reported for such links. Although turbulence did result in significant wandering and distortion of light signals, those error rates didn't prevent quantum links from successfully being established with either communication protocol. Unexpectedly, the researchers found they could keep quantum communication going even while the transmitter moved down the flume tank. "We had expected that this would not be possible without beam-tracking technology," says Felix Hufnagel, a lead author and quantum physicist at the University of Ottawa in Canada. After the scientists analyzed their data, they suggested the maximum distance for secure quantum communications might actually be 80 meters in turbulent water, although this would depend on factors such as the efficiency of the detectors used. Improving such factors might significantly boost the maximum communications distance, they say. The findings have been detailed in a preprint article on April 9.
The researchers achieved quantum communication at up to 72 kilobits per second across up to 30 meters of turbulent water, the longest distance yet reported for such links. Although turbulence did result in significant wandering and distortion of light signals, those error rates didn't prevent quantum links from successfully being established with either communication protocol. Unexpectedly, the researchers found they could keep quantum communication going even while the transmitter moved down the flume tank. "We had expected that this would not be possible without beam-tracking technology," says Felix Hufnagel, a lead author and quantum physicist at the University of Ottawa in Canada. After the scientists analyzed their data, they suggested the maximum distance for secure quantum communications might actually be 80 meters in turbulent water, although this would depend on factors such as the efficiency of the detectors used. Improving such factors might significantly boost the maximum communications distance, they say. The findings have been detailed in a preprint article on April 9.
Secondary benefit (Score:1)
And, if the submarine gets hit by a torpedo, we have a convenient test for Quantum Immortality [wikipedia.org]...
Quantum Link? (Score:3)
wow (Score:1)
Quantum Links (Score:2)
Scientists Explore Underwater Quantum Links For Submarines
Title and synopsis of the next J. J. Abrams film starring Scott Bakula as the holodeck-golf loving captain of a starship that spends most of its time submerging and surfacing in the oceans of various planets.
Quantum communication (Score:2)
Is this just normal communication with either entanglement or quantum computers for encryption on both sides?
Dumb it down for me, I'm dumb.
Sounds like military spending at its best (Score:2)
So did they find any.. (Score:2)
Grammar, I guess it don't learn itself.
Confusing words "Quantum link" (Score:2)
From the fine abstract: "a coherent superposition of beams carrying both polarization and orbital angular momentum, can also be used for underwater quantum cryptography."
But both the article and the abstract appear to sending signals one way through water.....they don't explain anything about two-way communication, or how being able to send light that is carrying polarization and orbital angular momentum information could be used for quantum cryptography.
Guess I'll need to read the finished paper when it's
EAM cut off (Score:2)
To the U.S.S. Alabama: Rebel-controlled missiles being fueled. Launch codes compromised, dissidents threaten to launch at continental United States, set DEFCON 2. Immediately launch ten Trident missile sorties." They're *fueling their missiles*! We don't have time to fuck around!
I thought there was no "free lunch" ..? (Score:2)
The headlines completely defy this claim, and I'm not sure who to believe.
Re: (Score:3)
The equivalent of one side of a one time pad [wikipedia.org] is placed in entanglement. You need the other side to do comms. That other side is transferred using normal communication.
What you actually do with 'quantum communication' is just a key exchange: place as many photons in entanglement as the size of your key. When you look at the photons you know how they stood. So you can form a key which you could consume only exactly once.