Inca Knots Inspire Quantum Computer

We think of data storage as a modern problem, but even ancient civilizations kept records. While much of the world used stone tablets or other media that didn’t survive the centuries, the Incas used something called quipu which encoded numeric data in strings using knots. Now the ancient system of recording numbers has inspired a new way to encode qubits in a quantum computer.

With quipu, knots in a string represent a number. By analogy, a conventional qubit would be as if you used a string to form a 0 or 1 shape on a tabletop. A breeze or other “noise” would easily disturb your equation. But knots stay tied even if you pick the strings up and move them around. The new qubits are the same, encoding data in the topology of the material.

In practice, Quantinuum’s H1 processor uses 10 ytterbium ions trapped by lasers pulsing in a Fibonacci sequence. If you consider a conventional qubit to be a one-dimensional affair — the qubit’s state — this new system acts like a two-dimensional system, where the second dimension is time. This is easier to construct than conventional 2D quantum structures but offers at least some of the same inherent error resilience.

The actual paper is paywalled at Nature. While the technique is exotic, it makes you realize that there is a lot to still shake out with quantum computers and just as today’s conventional computers don’t use tubes, core, and mercury delay lines, tomorrow’s quantum computers are likely to look very different than the ones we have today.

This isn’t the first time people have tried to create topological qubits, but the last time we noticed that effort there were some experimental problems. Want time on a quantum computer? You can access virtual ones. Or you can even use some real ones over the network.

19 thoughts on “Inca Knots Inspire Quantum Computer

    1. Buried in a desert 10,000 years, but left in a northern climate on the surface with lichen and moss and weathering, might be illegible in a couple of hundred.

      Interestingly, a shell was recently found with scratches attributed to hominids half a million years ago, it’s suggested it’s “art” but may also be the oldest data storage yet found.

    1. Those twits at bell labs will never do anything useful with sand. They should be working on improved tube designs.

      There is nothing guaranteed about basic R&D, but it’s average return beats anything except hookers and blow.

      Granting there is some historical cherry picking. Discounting R&D that involved eating shooms, astral projecting and other mystical nonsense. Only 19th century and on, no philosopher’s stone work included in calculation.

      R&D spending by the dunces also didn’t produce anything useful.
      Historical fact: About half history’s popes were proud dunces. Dunces believed that all useful knowledge was already written down in the bible and in the great Greek philosophers work. They were wrong. The meaning of the word is almost forgotten. Even when you see a dunce character in a movie (e.g. ‘Name of the Rose’) they aren’t named as such. Only the silly hat remains.

      I’m skeptical about quantum computers ever being practical. But don’t know enough to try and tell anybody else how to spend their money.

  1. This quantum computer uses ion traps that use lasers to stabilize/cool down ions.

    The whole phase of matter argument essentially just describes when matter behaves in a stable regular way, either in space (static), or in time (dynamic). Stable in time means ions follow a pattern in time, so while they are dynamic, they are so in a repeating fashion in time.

    So thinking of phase of matter is really a theoretical tool to understand how to stabilize matter, and thereby find ways to keep ions in superposition and not being affected by external noise (such as unwanted magnetic fields). It can be stable in space or in time.

    The other idea is to metaphorically weave the information/spread it out in space time to make it more stable. In other words, encoding the information in several dimensions at the same time to “anchor” it more strongly in spacetime, like the knots of incas.

    Now two (time) dimensions increase the effort, so they tried to achieve similar results by reducing it two one but still creating two independent/non-overlapping influences that affect the ions/stabilize them.

    The major message/takeaway is that ions are stabilized with two lasers pulsating with different frequencies such that the pulses of the two lasers never overlap in time. Since they never overlap you can consider it as if there were two time dimensions (one for each pulsating laser). The never overlap in time yet there is still a regularity to it (the two frequencies are derived from the Fibonacci sequence, see Scientific American article).

    In short:
    This regular behavior (vs, the natural noisy/chaotic behavior) is achieved with lasers. Phase of matter is more stable when “regularlization” is applied in several dimensions. So two lasers that attack it from two dimensions are better.

    One-dimensional time amplified the errors, “two dimensional time” (as mentioned above) however managed to stabilize it.

    The special trick is that they use theoretically two (time) dimensions which makes it more stable, but pratcially only one.

    Essentially the information is woven into space/time more and therefore is more stable.

  2. I tried to explain it but it seems to not have gone through.

    The major confusion comes from *theoretical* models that complicate the idea, such as phase, “two” time dimensions, and other abstract concepts, that give a birds eyes view/summary of the many complicated real world interactions on the quantum level. Even if those abstractions seem somewhat artifical, they allow easier theoretical reasoning, and thereby finding potential solutions for increasing stabiility in quantum systems.

    The solution itself just focuses on stabilizing the ions with two lasers, that create a pattern in time that counteracts external noise (e.g., from unwanted magnetic fields).

    Using two lasers instead of one and spreading the information in time (instead of localizing it in space, e.g., in the spin of a particle) anchors the information more firmly in space-time, and is therefore harder to disturb.

    This weaving in “two” time dimensions is where the inca knots are used as analogy, which spread information in space to make it more resilient to error.

    So the whole quantum computation (and states) are more stable, without needing mathematical error correction. It is physically less error prone from the get go.

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