back to article US boffins tangle with quantum entanglement in spooky rack-mounted networking hardware

American researchers have managed to successfully transfer entangled photons over a fibre network stretching approximately 11 miles, marking the longest-distance quantum entanglement experiment to take place in the US. This is not the largest quantum network ever – that honour belongs to a project in China – but what sets this …

  1. JassMan Silver badge

    Drop the quantum computer

    "This phenomenon, originally explored by Albert Einstein and Erwin Schrödinger, states that two or more particles can be made to exhibit certain physical properties, and the change to one particle will immediately change the other, even if they are miles apart. Einstein humorously referred to this as 'spooky action at a distance'."

    If they really do have instantaneous change over 11 miles, this could be the beginnings of an ansible. They should be working on getting worldwide instantaneous communication and if it works at room temperature, will be much easier to achieve than a supercold computer.

    OK a quantum computer is also a laudable aim but unhackable communications sounds much more achievable at the moment.

    1. Paul Kinsler

      Re: getting worldwide instantaneous communication

      Just to clarify, quantum entanglement does *not* give you instantaneous transmission of information.

      1. TRT Silver badge

        Re: getting worldwide instantaneous communication

        You can, however, do that with royalty. You just need a suitably rich supply of Princes and a King.

      2. steelpillow Silver badge
        Boffin

        Re: getting worldwide instantaneous communication

        At least, most physicists do not believe it does. The problem is that the information about what the entangled output means still has to be carried separately at or below the speed of light. But some still think they might find a way around it by agreeing a rigid procedure in advance.

    2. caffeine addict Silver badge

      Re: Drop the quantum computer

      Okay. Can someone explain this to me in words of one syllable? Maybe two.

      I was under the impression that you poked (a) and (b) spontaneously reacted in the same way. But this talk of fibre cabinets and repeaters seems to imply that there's a physical link between them. As do the above comments about the replication being as sub-light speeds.

      If they're physically connected, what is the (non-security) benefit?

      Or am I being dense? This is one of those subjects I thought I understood at uni 20-something years ago, but now just confuses the feck out of me.

  2. Chris G Silver badge

    Quantum computing is

    Right around the corner.

    Parked next to AI and Cold Fusion.

    Though in some ways it seems closer.

    Until you look at it.

    1. MiguelC Silver badge

      Re: Quantum computing is

      It is. And it isn't.

  3. terrythetech

    Neat trick, if you can do it!

    "These cells normally must be kept at absolute zero (-273.15°C or -460°F)"

    Near absolute zero maybe but not at absolute zero surely.

  4. Dwarf Silver badge
    Joke

    Poor patch management

    I've seen a fair few patch panels that cant be explained by "ordinary entanglement", so either there is a tangle monster that lives under the raised floor in data centres, or quantum entanglement is at work there too.

  5. adnim Silver badge

    One does not know the state of anything until it is measured.

    And if two entities are mutually exclusive, measuring one and discovering its state simply means the other was the opposite all along.

    Or does the one measured tell its mutually exclusive partner what to be? And if the communication is instantaneous, it still takes the speed of light to measure it.

    I still can't get my head around Bell's theorem though, it seems mutually exclusive to my level of intellect.

    Half joking/half confused could that be defined as some kind of entanglement?

    1. Dabbb Bronze badge

      Re: One does not know the state of anything until it is measured.

      Well, it's not exactly as easy as one is always opposite to another.

      It's about measurement and fact that once you measure one side of entangled pair it's wave function collapses into particle and this measurement causes collapse of wave function of second particle as well and it happens seemingly faster than information about performed measurement can travel between two particles.

      But since participle has to get to remote location actual information is carried by that particle at the speed of that particle which is slower or equal to speed of light, so no information transfer faster than speed of light is happening.

      Think of it as if you have single use magic network cable which can transfer information faster than speed of light but to transfer every bit you need pull new cable as previous one annihilates.

      p.s. and yes, I definitely don't understand how entanglement works, but my excuse is that no one else understands it either.

    2. swm Bronze badge

      Re: One does not know the state of anything until it is measured.

      Bell's theorem is merely an experimental setup where 2 entangled photons cannot have a hidden state that explains the weirdness. The experiment has been performed and Bell's theorem is violated so there is no hidden state in the photons. What is happening is that the 2-photon state has zero angular momentum and all measurements will conform to this fact. When the photons are far apart and the angular momentum of one photon is measured then we know that any measurement of the other photon will agree with this measurement.

      The "collapse of the wave function" gives a misleading picture of what is happening. Your view of the wave function is certainly different after the measurement but there is no time dependence on this collapse - the other photon might be measured before you do your measurement and your measurement just confirms the remote measurement. If the measurements are separated by a space-like interval then it is impossible to tell which measurement occurred first.

      Actually it gets weirder than this but the margins of this note are too small to elucidate.

  6. jonathan keith

    Science is amazing and all...

    ... but I'm getting to the age where I read an article like this and my first, instinctive, response is "burn the witch."

    1. jake Silver badge

      Re: Science is amazing and all...

      "Any sufficiently advanced technology is indistinguishable from magic." —A.C.Clarke

    2. Chris G Silver badge

      Re: Science is amazing and all...

      You may have stumbled onto something. There are sufficient significant numbers of practitioners of arcane sciences, that burning them may prove to be a resource even if it isn't very carbon neutral.

    3. mtfrank
      Facepalm

      Re: Science is amazing and all...

      Shit man. You owe me a new keyboard.

    4. Dan 55 Silver badge

      Re: Science is amazing and all...

      What you need is the late 2010s' version of the Hitchhiker's Guide to explain it for you:

      Quantum Computers Explained – Limits of Human Technology

      This YouTube channel is actually worth watching. Shame it's impossible to remember its name unless you're German.

  7. jake Silver badge

    "unhackable encrypted communications"

    Why do I have a mental picture of someone in a small office at a University somewhere rubbing his/her hands together and muttering "Challenge accepted."?

    1. amanfromMars 1 Silver badge

      Re: "unhackable encrypted communications"

      Why do I have a mental picture of someone in a small office at a University somewhere rubbing his/her hands together and muttering "Challenge accepted."? .... jake

      Hmmm? Is it an undeniable universally terrifying fact that hackable unencrypted communications ... and let us ponder on lengths of plain sensitive text and short cryptic entangling messages in any simple hyperlinking utility with complicated by early ignorant design facilities as such a vessel but no longer captured and servering exclusively to others as a convenient empty headed vassal ....... are the stuff of nightmares for those and that reliant on both exclusive future secrets for survival and executive administrative operation success?

      Greater IntelAIgent Games are On and All Systems are Go, jake? Fancy AI Challenges? And all from the comfort of computers and naked keyboards controlled by magic fingertips/almighty digits which may or may not be under your own full command and absolute control.

      1. Cliff Thorburn

        Re: "unhackable encrypted communications"

        This doesn’t involve more radiant radiation blasting brain cells back to opulent origins to be relayed back to LHC’HQ by Greater Operating Devices for confirmation of Alien Godly Beings temporarily in particle paradise (again!) does it? *shrugs*

        1. amanfromMars 1 Silver badge

          Re: "unhackable encrypted communications"

          This doesn’t involve more radiant radiation blasting brain cells back to opulent origins to be relayed back to LHC’HQ by Greater Operating Devices for confirmation of Alien Godly Beings temporarily in particle paradise (again!) does it? *shrugs* ..... Cliff Thorburn

          Certainly can do, CT, although permanently in particle paradises again and again is that which they would be realistically having to deal with ..... and excite/energise.

          Do IT right and everything is as a bottomless money pit which never stops giving ..... and that is a prime primitive primeval driver in many an exalted circle and vaulted cloister/high office and delightful dungeon.

          1. Cliff Thorburn

            Re: "unhackable encrypted communications"

            That read well until it came to the Delightful Dungeon part, insinuating the usual plot of diabolical great game escape room shenanigans and misleading melodrama followed by blame brain drain misdirection resulting in catastrophic causation and pandemic personal loss does it not?

            Alas the only way to win the game is not to play?, for outlandish outnumbering with secret zipped lips results in massive miscarriage of justice, and perpetrators holding an unfair advantage resulting in a wacky wild west rather than a right and rightful orderly new world.

            1. amanfromMars 1 Silver badge

              Plain Sensitive Text in Short Cryptic Entangling Messages

              That read well until it came to the Delightful Dungeon part, insinuating the usual plot of diabolical great game escape room shenanigans and misleading melodrama followed by blame brain drain misdirection resulting in catastrophic causation and pandemic personal loss does it not? ..... Cliff Thorburn

              That was just me being PC and inclusive of the bad and ugly, CT, until such times as they learn of and reject their predicament. It is only humane to give them something they can think to rule and reign over for so many of them are crazy enough to not think on their thoughts turning into actions which are self-defeating and totally revealing and it is nice to comfort them with their just desserts.

              And as for ...

              Alas the only way to win the game is not to play?, for outlandish outnumbering with secret zipped lips results in massive miscarriage of justice, and perpetrators holding an unfair advantage resulting in a wacky wild west rather than a right and rightful orderly new world.

              .... I'm sure all can agree ....

              The only way to get smarter is by playing a smarter opponent ….. Fundamentals of Chess 1883

  8. Neil Barnes Silver badge
    Boffin

    It's all very well...

    but is the cat alive or dead?

    Inquiring minds want to know!

    1. jake Silver badge

      Re: It's all very well...

      The Oracle has pondered deeply on your question, and after much deep thought has an answer:

      Yes.

      You owe the Oracle a rubber chicken and a coke.

      1. jmch Silver badge
        Thumb Up

        Re: It's all very well...

        "You owe the Oracle a rubber chicken..."

        +1 for Monkey Island reference!

        1. jake Silver badge

          Re: It's all very well...

          Monkey Island? Honestly, it's enough to make the Net.Sex.Goddess cry ...

    2. jmch Silver badge
      Thumb Up

      Re: It's all very well...

      It's alive....

      ...and dead.

      OK, it's either or both, or whatever. In any case it's much more satisfying to say

      <Frankenstein>IT'S ALIIIIIIVE!!!!!!</Frankenstein>

    3. Teiwaz Silver badge
      Windows

      Re: It's all very well...

      When it comes to cats, I agree with the Late Sir PTerry,

      The cat has three states,

      Alive,

      Dead,

      and Bloody Furious.

  9. steviebuk Silver badge

    Won't quantum...

    Computing end the saying "Have you turned it off and on again?"

    No because its on and off at the same time*

    *I'll get my coat. I known virtual nothing about quantum physics so don't know if that crappy joke even works :)

    1. steelpillow Silver badge

      Re: Won't quantum...

      "Computing end the saying "Have you turned it off and on again?"

      It depends whether you switch it back on in the same universe you switched it off in.

      1. Cynic_999 Silver badge

        Re: Won't quantum...

        Well, it sort of works. But instead of fixing the problem in your computer, it resets a computer on the other side of the World (though only if someone happens to be looking).

  10. Jay Lenovo Silver badge
    Holmes

    Sure it will work great

    "... will mark the first real quantum communication network in the world that truly connects quantum computing processors and memories using photonic quantum entanglement," Figueroa claimed.

    I guess you'd have to see it to believe it, but not anywhere in between?

  11. tallenglish

    Quantum is now a overused buzzword

    E.g. I had a quantum turd today, I both sharted and didn't at the same time.

    That said, entanglement needs photons from the same source - so any guff about instant communications is just that. Information can't travel faster than the speed of light EVER, its a law of the universe.

    Also Qubits will always require to be ultracold as they measure quantum spin and any heat will easilly break any entanglement (which requires spin to be exact - the less exact it is or the more interference from other sources like heat, the faster it falls out of entanglement). I think new computer tech will come when we can manipulate how molecules interact - E.g. molecular motors we can switch on or off with E/M field for example. Qubits and measuring spin is just too unstable at reasonable temperatures.

    Lastly repeaters - if you can repeat a signal, who is to say you can't also duplicate it at the same time (aka 3 entangled photons in T shape), so there is no guarentee communication isn't being snooped - just as we have the issue now with NSA and similar with wire taps. Granted this leaves only the governments that could spy, but it is usually them who do spy anyway.

    Quantum will come when AI can work out how to work with stable molecules or atomic spin - the hard part is getting those larger entities entangled in the first place, once achieved we likely could keep the in that state far longer which is far more usefull.

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