Catch up on stories from the past week (and beyond) at the Slashdot story archive

 



Forgot your password?
typodupeerror
×
Network The Internet

Engineers Achieve Quantum Teleportation Over Active Internet Cables 49

Researchers at Northwestern University have successfully achieved quantum teleportation over a standard fiber optic cable carrying regular internet traffic, demonstrating that quantum and classical communication can coexist on existing infrastructure. The research has been published in the journal Optica. TechSpot reports: Nobody thought it would be possible to achieve this, according to Professor Prem Kumar, who led the study. "Our work shows a path towards next-generation quantum and classical networks sharing a unified fiber optic infrastructure. Basically, it opens the door to pushing quantum communications to the next level." "By performing a destructive measurement on two photons -- one carrying a quantum state and one entangled with another photon -- the quantum state is transferred onto the remaining photon, which can be very far away," said Jordan Thomas, a Ph.D. candidate in Kumar's laboratory and the paper's first author. "The photon itself does not have to be sent over long distances, but its state still ends up encoded onto the distant photon."

Prior to this study, many researchers were skeptical about the feasibility of quantum teleportation in cables carrying classic communications. The concern was that the entangled photons would be overwhelmed by the millions of other light particles present in the fiber optic cables. However, Kumar and his team were able to devise a solution. Through extensive studies of light scattering within fiber optic cables, the researchers identified a less crowded wavelength of light to place their photons. They also implemented special filters to reduce noise from regular Internet traffic. Kumar explained that he and his team conducted a meticulous analysis of light scattering patterns and strategically positioned their photons at a critical point where the scattering effect was minimized.

To validate their method, the team set up a 30-kilometer-long (18.6 miles) fiber optic cable with a photon at each end. They simultaneously transmitted quantum information and high-speed Internet traffic through the cable. The quality of the quantum information was measured at the receiving end while executing the teleportation protocol by making quantum measurements at the mid-point. The results showed that the quantum information was successfully transmitted, even in the presence of busy internet traffic.

Engineers Achieve Quantum Teleportation Over Active Internet Cables

Comments Filter:
  • Teleportation? (Score:2, Interesting)

    by phfpht ( 654492 )
    If it requires cables, is it really quantum teleportation?

    I'm pretty sure that word means something else...

    And, I'm not really interested enough to either RTFA or RTFS
    • The article does not say much, it sounds like their reason for "teleportation" is for security. However this would only provide security over someone physically attacking the cable to get the comms content as I see it. Also since a long path (over 100km) would probably require multiple repeaters then the weak point would be in there. I doubt that they have a practical application from what the have discovered which I don't really know exactly what it is.
    • Re:Teleportation? (Score:5, Interesting)

      by Fly Swatter ( 30498 ) on Monday December 23, 2024 @09:09PM (#65035851) Homepage
      To answer your question: No.

      from tfa: quantum teleportation does not require the physical transmission of particles

      But they need a cable to: transmitted quantum information and high-speed Internet traffic through the cable

      The whole problem with quantum entanglement is that it is one-read and done. It's like sending an envelope with a pass-code that self destructs upon reading it. You can only use it once. It's ok for key sharing (like a password) but there is no repetitive random data transfer. You can't communicate an active data stream which is what all those seeking more funding want you to think.
    • Re:Teleportation? (Score:5, Informative)

      by JoshuaZ ( 1134087 ) on Monday December 23, 2024 @09:15PM (#65035859) Homepage
      Yes, quantum teleportation involves transferring a quantum state from one particle to another, but part of the process requires classical transmission always. Relevant xkcd https://xkcd.com/465/ [xkcd.com] .
    • Re: Teleportation? (Score:5, Informative)

      by daten ( 575013 ) on Monday December 23, 2024 @09:38PM (#65035889)
      Teleportation Does Not Avoid Transmission
      Quantum teleportation, another application of entanglement, still requires physically distributing entangled particles to the communicating parties. The quantum state of one system is "transferred," but the particles themselves must have been shared beforehand.
      • For the clueless among us is there any benefit to this? If the photons need to be sent then you're limited to light speed travel. If the quantum information is destroyed when it's observed (is it?) then doesn't that photon cease being useful after a single bit is transferred? Is there a practical benefit here, or is my (lack of) understanding the problem?

        • The fiber is used to move an entangled photon. After it gets to the destination the fiber is not needed because 'the information', the particle's state can can be manipulated by the sending side and observed at the destination . " The information " is conveyed (but not transmitted) via the quantum effects .
          • What quantity of quantum 'information' can be observed per photon?

            Does the photon cease to be useful after the observation, where transferring more quantum information would require one or more additional entangled photons?

            • Last time I checked, the spin of the photon was "the information"... for instance , clockwise=0, counterclockwise =1.

              If you change the spin on one end , and observe that on the other end, "information" was conveyed.
    • Quantum seems like just another buzzword now, like AI. People say things like "quantum-like" and "quantum-inspired" algorithm. I don't know quantum, so I have no idea what any of this means, but it puts quantum in the same category as AI: the next technology to hype, pump, and dump. I hear/read so many conflicting things but have not seen any demonstrated value or financially viable use cases. For me, crypto (currencies) will never be a valid use case.
      • A lot of research is going into (and a lot of researcher careers are being devoted to) quantum right now because, if it pays off, it'll fundamentally change a wide range of computing and engineering disciplines. However you really can't ignore that if - it's not a given that it's going to pan out at all. But the payout, if successful, will be huge.

        • Not sure where I heard this, but "There's a big difference between impossible and *almost* impossible." I feel like that applies here somehow, or maybe some type of converse statement. I think it may be beyond my capacity to understand.
          • It's more likely beyond the capacity of a journalist to understand, which is why they can't explain it in a way that the average person can understand. This [wikipedia.org] is a better explanation.

      • I'm using AI to design a machine that can allow me to make a Quantum Leap. We'll call it a Quantum Accelerator. Then when I step into it, I can get hopelessly lost, leaping through other peoples lives, guided only by my quantum computer known as Ziggy. Eventually, I leap into some guy called Johnathan Archer and fight the Suliban in a temporal cold war, and then the Xindi. Then the temporal cold war suddenly gets redacted in the Next Generation. Hold your applause, I'm here all week.

      • OK, well, this is a legit quantum story. It's a direct application of quantum physics, and is already useful for secure key exchange, for when you "really, really" care.
        • Cool! Glad to hear progress made. I'd love to understand more. Maybe I'll ask an LLM to summarize... thanks!
        • 'already'? So you are saying there is an actively used quantum key exchange implementation that we just don't know about?

          whoever coined the teleportation description is either a marketing genius or a clever scam artist - since nothing is teleported, those entangled particles have to be delivered first to the destination and this always takes some measurement of time.

          -dons tinfoil hat

          teleport
          verb
          (especially in science fiction) transport or be transported across space and distance instantly.
      • by necro81 ( 917438 )

        Quantum seems like just another buzzword now

        "Now" as in, for over a century?

        There's legitimate (not vaporware) uses for sticking "quantum" in front of certain things. Generally, it means taking advantage of the weirdness that arises from quantum mechanics. In particular, entanglement [wikipedia.org] and superposition [wikipedia.org]. Wikipedia's explanations are rather dense, but you have the entire Internet at your disposal: I suggest you brush up on it.

        In the case of TFA, they're talking about getting a couple of photons into

        • Yours is an extremely valuable post; thank you! Best summary I've read on both topics. I don't even understand entanglement, how that works, how it is possible, how it is reliable. But I trust those that know much more than me.

          From what I've seen, I think a difference between quantum and AI (or at least, LLM) is that quantum is based on theory. Nuclear weapons and space travel probably seemed impossible when they were just theory. But there is no theory to suggest that LLM will pay off as people expect,
          • by necro81 ( 917438 )

            Do you mind if I copy bits of this to another channel....Meh, what's the point of asking for permission these days

            [shrug] Public forum on the Internet, go ahead and use (with attribution).

        • by HiThere ( 15173 )

          That's not quite correct about quantum computing. I believe that the relaxation approach to quantum computing has actual uses. Of course, it's not a generally applicable approach, and only works for a specific class of problems (that, IIUC, don't include factoring numbers). But there are special cases where it's useful even at the added expense. (Well, at least some companies seem to purchase D-Wave quantum computers.)

      • Maybe one day we'll have quantum advertising, where the tendency toward enthusiasm exhibited by the seller can be directly transferred into the mind of the victim/potential customer ?

    • Quantum entanglement and teleportation are two distinct and separate things but not many are capable of distinguishing the two.
    • Teleportation is a buzzword, every time i open my browser a website magically teleports into it like slashdot.org, and when i call a family member or friend we teleport our voices to eachother, same with text messaging is just teleporting text, now i have to take my morning walk after teleporting this comment to slashdot, have a nice day teleporting:)
    • If it requires cables, is it really quantum teleportation?

      I'm pretty sure that word means something else...

      And, I'm not really interested enough to either RTFA or RTFS

      Quantum teleportation does not mean what you seem to think it means. It is not about transmitting physical objects, but rather transferring quantum states using entanglement and classical communication. The cables in this experiment are necessary to carry both the classical information required for the process and the photons involved in generating and measuring the entanglement.

      In this context, the term "quantum teleportation" is precise and appropriate. The state is destroyed at one location and reconstru

  • One entangled photon is delivered via the fiber , but the entangled state is what delivers the information.

    You don't teleport the particle , metaphorically you teleport the information .
    • by Big Hairy Gorilla ( 9839972 ) on Monday December 23, 2024 @10:24PM (#65035931)
      Teleportation is used as a metaphor, because no information is moved nor transmitted. The photon is in both places at the same time, so any change can be seen by both locations .

      So, information is not moved , thus the term teleportation is not accurate . It just sounds cool . Information be conveyed but nothing moves . Once you deliver the entangled photon, you don't need the fiber anymore.
      • The photon is in both places at the same time, so any change can be seen by both locations - Oh boy. This is an example of why no one understands entanglement.
      • In layman's terms it's like rubbing your nuts together real hard, then you separate them by annnnnny distance.

        With lots of hand waving we say it's now one nut, bruised on a side. If we dissect it to observe the bruising pattern on the nut in one location, we instantly know the bruising pattern of the nut in the other location via *hand waving* _teleportation_ of the information.

        The only practically useful feature of this protocol is when a nut has been transferred to the remote end we can be assured it has

      • Teleportation is used as a metaphor, because no information is moved nor transmitted. The photon is in both places at the same time, so any change can be seen by both locations .

        So, information is not moved , thus the term teleportation is not accurate . It just sounds cool . Information be conveyed but nothing moves . Once you deliver the entangled photon, you don't need the fiber anymore.

        Your comments reflect a common misunderstanding of both metaphor and quantum mechanics. "Teleportation," in the context of quantum physics, is not merely a metaphor -- it is a technical term rooted in the precise mechanics of transferring quantum states. The term was first defined in a 1993 paper by Bennett et al., and it accurately describes the process of destroying a quantum state at one location and reconstructing it at another. This does not involve the particle itself being "in two places at once," n

        • I'm not going to claim I understand all that much of quantum computing but I'm fairly sure of the following: ONLY ONE entangled photon of the photon pair is moved (via the fiber), and the quantum effects (teleportation in this case) does NOT rely on the fiber in any way.

          I'm also going to qualify and withdraw my previous statement "one object in two places" which was a dumbing down on my part to communicate.

          Secondly, when I said "teleportation" is misleading, it is misleading in a colloquial sense. I'll be h
  • And research takes funding, so you're going to hear more things like this.

    Teleportation protocol? At what layer do they implement that?
  • Weird terminology in the title. An "active cable" in my book is one that receives and re-transmits a signal.
    Such a cable would break the quantum transmission properties (unless they would be made part of the scheme itself)

    Some cables often called "active optical cables" have electric connectors but uses a fibre to send the signal. (i.e. transmitted and receiver are part of the cable). There exist such active cables for e.g. USB and HDMI for longer ranges.

    • The world has more functions than it has words to describe something. Even Slashdot's darling open source struggles with the concept of free as in libre, or free as in beer. What does open mean? That I can see the source code, or that any hacker can get access to my system without a password?

      Active fibre in this context means the opposite of dark fibre. i.e. they are in active use. Context is critical for the english language.

  • Soon, unwanted ads may be accompanied by real cans of spam, beamed into that part of your field of view most interesting to you.

"Inquiry is fatal to certainty." -- Will Durant

Working...