Quantum Entangled Computer Memory Over 30 Miles Enables Quantum Internet

Chinese scientists have transmitted quantum computer memory between two entangled clouds of atoms over 50 kilometers. They developed an efficient atom-photon entanglement source that is suitable for low-loss transmission in fibers. This means a quantum internet could span a large city network.

They entangled two clouds of a billion atoms then extracted a photon from each cloud.

A quantum internet that connects remote quantum processors should enable a number of revolutionary applications such as distributed quantum computing. Its realization will rely on entanglement of remote quantum memories over long distances. Despite enormous progress, at present the maximal physical separation achieved between two nodes is 1.3 kilometres, and challenges for longer distances remain. Here we demonstrate entanglement of two atomic ensembles in one laboratory via photon transmission through city-scale optical fibres. The atomic ensembles function as quantum memories that store quantum states. They used cavity enhancement to efficiently create atom–photon entanglement and we use quantum frequency conversion to shift the atomic wavelength to telecommunications wavelengths. They realized entanglement over 22 kilometers of field-deployed fibers via two-photon interference and entanglement over 50 kilometers of coiled fibers via single-photon interference. The experiment could be extended to nodes physically separated by similar distances, which would thus form a functional segment of the atomic quantum network, paving the way towards establishing atomic entanglement over many nodes and over much longer distances.

Nature – Entanglement of two quantum memories via fibres over dozens of kilometers

16 thoughts on “Quantum Entangled Computer Memory Over 30 Miles Enables Quantum Internet”

  1. Feline-arca self assembly only works if you don’t want the cat in the box.

    As with all quantum things, it depends on the observer.

  2. Tress don’t make noise if no one is around. Noise is only noise once it’s picked up inside the ear, otherwise it’s just vibrations of air if no one is around to hear it…

  3. Experimental attempts to actually stuff a cat into a box resulted in the human ending up halfway between life and death, while the cat strutted away in victory.

  4. does that mean you can put a cat in a box 30 miles away and keep them in a propetual quantum flux between life and death until you decide his fate… The trees in the forest say yes by making a noise by falling over…

  5. Seems to be more about directly networking quantum computers over great distances and the development of (low-loss transmission) bandwidth that is not vulnerable to photon line loss that occurs when quantum data sets stream over fiber-optic lines, than about taking the limits of physics as we currently understand it out towards the realms of Star Trek.

    Greater distance entanglements means more quantum computers across a country or across the globe can link up to exponentially compound their already quantum processing power.

    Says the experiment was successful in the lab with a 50km roll of fiber optic cable, so the assumption is that it can be replicated over existing networks. The experiment noted in the article is significant, yet at present, there are likely not many quantum computers within 50km of each other, therefore the nearterm outlook is that quantum computers will continue a lonely existence until the distances over which they can move their quantum data sets between each other is significantly increased.

  6. I think almost everyone from US/UK visiting this site can do the mental transformation from metric to imperial.

  7. Why does this author still have problems with metric?
    This website targets the whole world where 99% of the countries have gone metric. The article is completely metric. Then why change the title suddenly back to imperial?

  8. Don’t fully understand either, but I think the transmission is still conventional photons-over-fiber-optics at the usual light speed in a fiber (which IIRC is a little slower than in vacuum). This is more about encryption and about connecting quantum computers.

  9. I’m not sure I understand. Is this a potential long-hypothesized “subspace” quantum entanglement communication technique? You know, how people in Star Trek manage to communicate between starships all over the galaxy and Earth or Star Fleet, without having to wait hundreds or thousands of years for speed of light bound responses? If it’s just Earth bound fiber-optic constrained communications, then yawn, who cares?

  10. Yeeees!!! Hopefully this kind of development can be quickly replicated and grown rapidly around the globe. I wonder what it would mean for userspace? What kinds of noticeable enhancements would we see in our everyday rummage through society? A lot of it would be on the back end, of course. Perhaps [Internet] backbones could decrease in size, etc? We could see small devices connected in ways they haven’t been, before. Forget RSA keys; quantum SSL for everyone (and now I’m just talking out my… yeah). Fun stuff, though.

    Then again… do I really WANT a society that moves faster than it already does? There’s much to be said for slowing the heck down. T_T

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