Comment by EvgeniyZh

3 days ago

I'm doing theorical research in the topological quantum computing.

The idea behind topological quantum computing is to utilize quantum materials whose low-energy physics looks like an error correcting code. Since these systems are very large (macroscopic number of atoms), the error rates are (theoretically) very low, ie the qubit is fault tolerant by construction, without any additional error correction. In reality, we do not know how good these qubits will be at finite temperature, with real life noise, etc.

Moreover, these states do not just occur in nature by themselves, so their construction requires engineering, and this is what Microsoft tries to do.

Unfortunately, Majoranas in nanowires have some history of exaggerated claims and data manipulation. Sergey Frolov's [1] twitter, one of the people behind original Majorana zero bias peaks paper, was my go-to source for that, but it looks like he deleted it.

There were also some concerns about previous Microsoft paper [2,3] as well as the unusual decision to publish it without the details to reproduce it [4].

In my opinion, Microsoft does solid science, it's just the problem they're trying to solve is very hard and there are many ways in which the results can be misleading. I also think it is likely that they are making progress on Majoranas, but I would be surprised if they will be able to show quantum memory/single qubit gates soon.

[1] https://spinespresso.substack.com/p/has-there-been-enough-re...

[2] https://x.com/PhysicsHenry/status/1670184166674112514

[3] https://x.com/PhysicsHenry/status/1892268229139042336

[4] https://journals.aps.org/prb/abstract/10.1103/PhysRevB.107.2...

I’m an experimentalist at Microsoft Quantum who was involved in the work presented in our recent Nature publication. As an experimentalist, I can say these results are very exciting and would emphasize that the data are coming from real devices in the lab, not just theories. In the Nature paper, we present data from two different devices to demonstrate that the results are reproducible, and we performed additional measurements and modeling described in the supplemental material to rule out potential false positive scenarios.

In my opinion, the citations above do not represent a balanced view of the Majorana field status but are rather negative. We published two experimental papers recently that went through a rigorous peer review process. Additionally, we have engaged with the DARPA team to validate our results, and we actually have them measuring our devices in our Redmond lab.

Finally, we have exciting new results that we just shared with many experts in the field at the Station Q conference in Santa Barbara. These new experiments further probe our qubits and give us additional confidence that we are indeed operating topological qubits. We will share more broadly at the upcoming APS March meeting. For more information, please see the following post by my colleague Roman Lutchyn: https://www.linkedin.com/posts/roman-lutchyn-bb9a382_interfe... ."

  • > I’m an experimentalist at Microsoft Quantum who was involved in the work presented in our recent Nature publication.

    It is very cool to hear from you!

    > In my opinion, the citations above do not represent a balanced view of the Majorana field status but are rather negative.

    That's true, but the goal of the citations was to demonstrate there are some negative opinions too. Maybe together with positive OP these form a balanced view.

    I understand that it can be very unpleasant to have people like Frolov or Legg trying to prove you're wrong, but I think it shoudn't be personal (from either side). Trying to find alternative explainations is part of science. And Frolov did turn out correct in past, and we did think we found Majoranas when in fact we didn't, and this part of the story can't be just ignored. Citing Feynman "The first principle is that you must not fool yourself and you are the easiest person to fool". While it's tempting to dismiss the critics as broken record, I think it would both increase the credibility of the studies and improve the science if their criticism was taken at the face value. Answering specific points publicly would also create more balanced picture. I'm not aware of the responses to the cited opinions that I could cite to "balance out."

    > We published two experimental papers recently that went through a rigorous peer review process.

    Peer review is important, but is not the answer to specific claims, eg that TGP accuracy is overestimated, or (if we take Henry's word for it) the promised errata that never came out.

    > Finally, we have exciting new results that we just shared with many experts in the field at the Station Q conference in Santa Barbara.

    I've read about it from Das Sarma's twitter [1]. It does indeed sound exciting. If you're able to manipulate, store, and read out quantum data from qubit, then I think people will have easier time to agree you have one. There is of course question of non-Clifford gates, but that's a separate problem.

    > We will share more broadly at the upcoming APS March meeting.

    I look forward to hearing about it. If you (or someone from your team) are interested, I'd love to meet and chat at MM. My contacts are in bio.

    Edit: I've also now seen Chetan Nayak's comment in Scott Aaronson blog with some details [2].

    [1] https://x.com/condensed_the/status/1892595693002293279

    [2] https://scottaaronson.blog/?p=8669#comment-2003328

I know nothing about quantum computing, but constructing a physical system that resembles error correcting codes sounds absolutely fascinating.