A Quantum Internet Connected By Cargo Ships Is Not As Crazy As It Sounds

A Quantum Internet Connected By Cargo Ships Is Not as Crazy as It Sounds

Our internet has a physical infrastructure: thousands of kilometres of cables that criss-cross the oceans. The quantum internet, when it exists, will have a physical infrastructure too. But you can't send quantum bits, or "qubits", on fibre optic cables, so a group of physicists has proposed a bizarre solution: cargo ships carrying data on diamond-based drives. And it's not a completely whacky idea.

There are myriad reasons we do not yet have a quantum internet, but one of them is that we can't send quantum information over long distances. City-wide networks are being built, but they only cover distances of 160km or less.

To build larger quantum networks, we'll need devices called quantum repeaters to boost the signal. But those things are tricky to build. For one, as Tech Review notes, they have to be kept close to absolute zero. Good luck building a super-fridge at the bottom of the Pacific Ocean.

Instead, a group of physicists argue we should take a page from the sneakernet, aka transferring data on physical disks and drives. Massive container ships could cross our oceans carrying diamond-based hard drives, which are especially stable. Shipping might seem agonisingly slow for everyone used to instant videos, but the quantum internet will also be completely secure due to the laws of physics. Anyways, cargo ships are huge. A ship carrying 10,000 containers worth of quantum bits that crosses the ocean between Japan and the US would still come out to a data transfer of up to 1TB per second.

Obviously, this is all a theoretical exercise, but it highlights a legitimate and important problem for the quantum internet. The internet, quantum or not, isn't just information magically appearing on our screens but physical structures that have to be designed, built and maintained. [Tech Review]

Picture: AlexKol Photography/Shutterstock



    Disclaimer: I know next to nothing about Quantum Physics, so little that this may make someone who does know what they're talking about cry.
    We currently have/nearly have the ability to entangle two qubits together no? This entanglement allows 2 particles to interact over distance without standard physical interactions. Could this be used to, for example, have 1 read and one write bit in New York and the same in Sydney? You would change the state of your write bit and they would observe the results and vice versa.

    Again, I may have misunderstood something and I am aware that there is still (and may never be) a way to transfer information faster than the speed of light so there would still be a delay, but I'd imagine might lower than a cargo ship.

      Unfortunately, that is not how quantum teleportation works, it is nothing like teleporting in the conventional/pop culture sense. Short answer, quantum teleportation cannot transfer any message that you may want to send.

      Longer answer/basic explanation: think of qbits(technically, they are particles that store qbits) as dice, what entagling does is link a pair dice, if one die is rolled, the second will then also give the same result when rolled (in effect, 'teleporting' the result). The problem is, the first dice to be rolled gives a random result, it cannot be controlled (and this is a theoretical die for my analogy so no you cannot tamper with it or just put it down on the number you want) meaning you cannot use it to send a message (i.e. you cannot 'write' to a die being rolled).

      However as you may know, this is far from useless, one application is for cryptography, you can for example use this qbit to transfer your password/key as attempts to tamper with it will mess up the entanglement.

      I don't understand Quantum physics either, but I've heard the explanation of entanglement enough times to know why it doesn't work for this:
      All that happens is that the two bits happen to be exactly opposite of each other, no matter how far away they are, they stay in opposite states, but you don't know what state either is in until you manage to measure one of them. When you measure one then you know what state the other was in when you did that measurement.

      It's impossible to transfer information that way because it's random. You can't force one bit to be in a state (spin up) and so transfer info by knowing the other bit be in the spin down state because all you'd do is break the entanglement. All you can do is observe and what you observe is random.

      It's like dropping two balls on the ground in two separate rooms and knowing that they'll always be doing the exact opposite of what the other ball is doing until they finish bouncing, but you can't influence the ball in the other room by doing something to one of the balls, all you end up doing is breaking the sequence.

        Thanks that makes perfect sense, I figured there was a reason why this wasn't being explored as an option.

          No worries.
          It's not a perfect explanation by any means, but I did try to demystify the concept a bit.

        Dice is wrong analogy. Dice have a limited set of possible values. This can be used to transfer data with the understanding that a '1' can be when the dice is being rolled. The value of the roll becomes irrelevent. Only the edge of the pulse is needed. If qbits are random and you can only observe what state the bit is in once it is rolled then you need a mechanism where you say lets use this qbit because it is a '1' and we need to transmit a '1'.

          I didn't use a dice analogy. Even so I find you explanation impenetrable.

    There are myriad reasons we do not yet have a quantum internet, but one of them is that we can’t send quantum information over long distances. City-wide networks are being built, but they only cover distances of 160km or less.
    Where are city-wide quantum networks being built?

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