I'm doing theorical research in the topological quantum computing.<p>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.<p>Moreover, these states do not just occur in nature by themselves, so their construction requires engineering, and this is what Microsoft tries to do.<p>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.<p>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].<p>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.<p>[1] <a href="https://spinespresso.substack.com/p/has-there-been-enough-retractions" rel="nofollow">https://spinespresso.substack.com/p/has-there-been-enough-re...</a><p>[2] <a href="https://x.com/PhysicsHenry/status/1670184166674112514" rel="nofollow">https://x.com/PhysicsHenry/status/1670184166674112514</a><p>[3] <a href="https://x.com/PhysicsHenry/status/1892268229139042336" rel="nofollow">https://x.com/PhysicsHenry/status/1892268229139042336</a><p>[4] <a href="https://journals.aps.org/prb/abstract/10.1103/PhysRevB.107.210001" rel="nofollow">https://journals.aps.org/prb/abstract/10.1103/PhysRevB.107.2...</a>
Are these actually even useful yet? Genuine question. I never managed to solicit and answer, only long explanations which seemed to have an answer of yes and no at the same time depending on who you observe.
Whoever decided to make up the non-existent term "topoconductor" for the purposes of this article deserves to feel shame and embarassment (I say this as a condensed matter physicist).
From a casual observer, it seemed like Microsoft's Majorana approach had hit a wall a few years back when there were retractions by the lead researchers. I wonder what's changed?<p><a href="https://cacm.acm.org/news/majorana-meltdown-jeopardizes-microsofts-quantum-computer/" rel="nofollow">https://cacm.acm.org/news/majorana-meltdown-jeopardizes-micr...</a>
How the H devices (which they call tetrons) form a qubit is explained more thoroughly in their ArXiv article: <a href="https://arxiv.org/abs/2502.12252" rel="nofollow">https://arxiv.org/abs/2502.12252</a>
Discussion on other official post: <a href="https://news.ycombinator.com/item?id=43103623">https://news.ycombinator.com/item?id=43103623</a>
Short Term - This might be hype. Sure. Getting some Buzz.<p>Long Term - MS seems pretty committed and serious. Putting in the time/money for a long term vision. Maybe a decade from now, we'll be bowing down to an all powerful MS God/Oracle/AI.
> Microsoft’s topological qubit architecture has aluminum nanowires joined together to form an H. Each H has four controllable Majoranas and makes one qubit. These Hs can be connected, too, and laid out across the chip like so many tiles.<p>So they are not all in a superposition with each other? They talk about a million of these nanowires but that looks a bit like quantum dots?
A few things to keep in mind, given how hard of a media push this is being given (which should immediately set off alarm bells in your head that this might be bullshit)<p>- Topological phases of matter (similar, but not identical to the one discussed here) have been known for decades and were first observed experimentally in the 1980s.<p>- Creating Majorana quasiparticles has a long history of false starts and retracted claims (discovery of Majoranas in related systems was announced in 2012 and 2018 and both were since retracted).<p>- The quoted Nature paper is about measurements on <i>one</i> qubit. One. Not 100, not 1000, a single qubit.<p>- Unless they think they can scale this up really quickly it seems like its a very long (or perhaps non-existent) road to 10^6 qubits.<p>- If they could scale it up so quickly, it would have been way more convincing to wait a bit (0-2 years) and show a 100 or 1000 qubit machine that would be comparable to efforts from Google, IBM, etc (which have their own problems).
> Majoranas hide quantum information, making it more robust, but also harder to measure. The Microsoft team’s new measurement approach is so precise it can detect the difference between one billion and one billion and one electrons in a superconducting wire – which tells the computer what state the qubit is in and forms the basis for quantum computation.
Can someone check my understanding: does this mean they have eight <i>logical</i> qubits on the chip? It appears that way from the graphic where it zooms into each logical qubit, although it only shows two there.<p>If that is true, it sounds like having a plan to scale to millions of <i>logical</i> qubits on a chip is even more impressive.
NYT feature: <a href="https://www.nytimes.com/2025/02/19/technology/microsoft-quantum-computing-topological-qubit.html?unlocked_article_code=1.yE4.2nFS.zYDdtb75cSKT&smid=url-share" rel="nofollow">https://www.nytimes.com/2025/02/19/technology/microsoft-quan...</a>
I want a children’s picture book of majorana topologies, they are so beautiful! <a href="https://ars.els-cdn.com/content/image/1-s2.0-S2590238522001734-gr13.jpg" rel="nofollow">https://ars.els-cdn.com/content/image/1-s2.0-S25902385220017...</a><p><a href="https://qdev.nbi.ku.dk/research/topological_quantum_systems/Topological_quantum_systems_pic_1.png" rel="nofollow">https://qdev.nbi.ku.dk/research/topological_quantum_systems/...</a>
Scott Aaronson's FAQ on Microsoft’s topological qubit thing<p><a href="https://news.ycombinator.com/item?id=43112021">https://news.ycombinator.com/item?id=43112021</a>
I just want to acknowledge the general lucidity of this community, also finding out I am not insane is bit of a bonus. love this community, please don't change
Nadella is currently claiming on X that this opens up a "direct path to 1 million qubits". Based on my priors, I put the probability of this statement being horseshit at 99.9%. Could someone knowledgeable make it 100%?
If it's going to take another 10 years to turn this into a usable product...
Better spew out some marketing BS to move the needle on MSFT stock price...
> Microsoft unveils Majorana 1 quantum processor<p>What is Win 11 boot time on this processor ? Will it be supported in the next version of Windows ? /s