Do you happen to have a source on the simulation piece? Curious what they criterions were for a single functional neuron

]]>Microsoft and Google take different physical approaches to accurate qc. However, the approaches use isomorphic math, topological protection. I strongly suspect the stability and accuacy of their logical qubits will be similar.

An analogy for topological protection:

The cells of a tree are connected in a way that can easily be seen as a mathematical graph where the vertices are the cells and the edges are the physical connections of the cells. When a modest wind blows, the tree cells adjust so that the tree sways and doesn’t break. That is, the graph is protected. The topology is preserved. If a tornado hits the tree, well so much for the topology. The tree is topologically protected naturally for winds below some energy threshold. This is the Microsoft path to qc.

Now imagine if Boston Dynamics built a ‘tree’. It would have a trunk and branches made of small rigid pieces connected through joints who’s angle are controlled by computers that are fed stresses from sensors through out the tree. This tree would also be topologically protected from the wind below a threshold. This is the Google way to qc.

The difference is Microsoft is creating a physical system that is protected by natural forces in the system. Google controls its system with a computerized correction mechanism. They are using the same mathematical, physical principles.

]]>The extended Church Turing thesis says reality is in BQP. Evaluating knot polynomials is BQP complete. So it follows, if you assume ECTT that, from one point of view, reality is knot polynomials! More specifically in qc, these are knot polynomials on braids of paths of anyons moving through 3d spacetime (holographically correct). Of course all of this was just math. Noone ever implemented these types of transforms of quantum states, until now!

Congratulations to all involved. History will view this work as of highest importance.

In the 80s, the Jones polynomial was a lightning bolt

that shocked the field of topology. I heard one topologist describe it as if he had look up in the night sky and a new star appeared. Even that topologist would not have imagined its phisical significance.

I am sure a book will be written: Jones, Witten, Frohlich, Kitaev, Freedman, etc… I cannot wait to read it. Beautiful. We are all knot polynomials.

]]>I am not denying the difference between simulation and actuality. A hydrogen atom simulated on a qc is not hydrogen. The defining property of hydrogen is a proton and an electron. A qc simulation would not have these.

In the case of an anyon, the defining property is braiding statistics of quantum states. You may define anyon as specific to solid state, in which case I agree that these types of anyons are not in the qc. Isn’t the important thing for qc that someone create braiding statistics so that a necessary but not sufficient condition for this type of error corrected qc is demonstrated?

Did the work create braiding stats that are necessessary for Google’s approach to error corrected qc? Is it a demonstration of braiding stats as soild state anyons would have or something different? If it is different, what is different?

]]>Rather than going down this metaphysical rabbit hole, an alternative is to ask what a given advance is actually good for. In this case, the problem with using these nonabelian anyons for QC is presumably that they won’t survive for very long … because the underlying superconducting qubits that constitute them won’t survive for very long either! And if you solved that problem, then you’d already have a scalable superconducting QC and wouldn’t need the nonabelian anyons. How am I wrong?

It’s become clear to me that we’re going to see more and more claims of “bringing something into actual physical existence” because someone simulated it on a small number of qubits in some superconducting or ion-trap system. I think we need to get into the habit, fast, of not according those claims a special metaphysical status just because the computer doing the simulation happens to be quantum rather than classical.

]]>In the case of surface code, the safe qubits exist in every sense that electrons do or the way non-Abelian anyons are hypothesized to exist. So the case seems stronger for surface code anyons than computers computing.

]]>These results seem ground breaking in the largest sense. Braiding operations exist on quantum systems!!!!!! It is not a simulation of braiding, it is braiding. Am I missing something?

]]>Why does this matter? For one thing, a central reason why people care about nonabelian anyons, is as building blocks for a universal quantum computer. But if you already need a universal quantum computer *before* you can see the anyons, that use is pretty much ruled out! 🙂

Curiously that word does not appear in the paper.

]]>America has problems, but reports of its death are greatly exaggerated.

]]>