5 ms·
It's not a big mystery how this will get accomplished however, which is why participants in the field seem hopeful (if modest and tempered). The theory of quant
by reikonomusha 3y ago
It's not a big mystery how this will get accomplished however, which is why participants in the field seem hopeful (if modest and tempered). The theory of quantum error correction is rich and pretty well developed. It's just that engineering a system which has enough runway to be error corrected requires a lot of development and innovations in a lot of directions: qubit design and fabrication, quantum compilers, rapid experimental procedures, etc.
Edit to edit: Thinking of gate depths as permitting such-and-such megabyte databases as being "uploaded" isn't really a good or accurate metric in my opinion.
- fxj 3y agoWhat puzzles me with IBMs roadmap is their scaling: 2025 156 qubits, 5000 gates 2028 156 qubits, 15K gates 2029 200 qubits, 100M gates 2033 2000 qubits, 1B gates The jump from 15K to 100M gates looks fishy to me. Maybe I am wrong but I doubt that will work that way.
- mettamage 3y agoThe key is to give an optimistic roadmap and then work on delivering it as fast as possible. Maybe I am getting a bit cynical but it seems that is what all companies and workers are doing.
- pclmulqdq 3y agoLying enough to get people excited to fund you, but not quite enough to catch a fraud charge.
- echelon 3y agoThere's a huge difference between saying "we can do" and "we think we will be able to do".
- oldgradstudent 3y agoThe real difference is between "we think we can do it" and "we think we can get away with saying it".
- layer8 3y agoIt reads like wishful thinking, or an upper bound of what could happen in the best-case scenario.
- sampo 3y agoWhen will they (or anyone) be able to run Shor's algorithm to factor the number 35? There was a failed attempt in 2019. https://en.wikipedia.org/wiki/Shor%27s_algorithm#Physical_implementation https://en.wikipedia.org/wiki/Shor%27s_algorithm#Physical_im...
- sesm 3y agoError correction can fix bit flips, but how can it help if qubits loose entanglement?
- sebzim4500 3y agoIt's an unintuitive theorem in quantum computation that as long as you can protect against two types of errors (bit flips and sign flips) you are protected against almost all errors.
- sesm 3y agoWhen qbits are not entangled, quantum computer doesn't exist anymore, this is not a kind of error that you can correct.
- eigenket 3y agoThere isn't a good non-technical answer to your previous question but lemma 3.3 of this paper [1] says that if you can correct a finite set of errors for each qubit individually then you can also (essentially for free) correct all other errors. Specifically if you correct a set of errors which spans the set of possible errors (for example the Pauli errors on each qubit do this) then you correct all errors. This is essentially the reason people are still interested in quantum computing, and why quantum error correction is viable at all. You can protect highly entangled crazy states from highly non-local complicated errors using only the resources needed to correct simple local errors. [1] Key ideas in quantum error correction, Raussendorf 2012: https://royalsocietypublishing.org/doi/10.1098/rsta.2011.0494 https://royalsocietypublishing.org/doi/10.1098/rsta.2011.049...
- fxj 3y agoCan you also compensate against decoherence? I thought this is the magic limit when the QC breaks. See also: https://blogs.scientificamerican.com/observations/decoherence-is-a-problem-for-quantum-computing-but/ https://blogs.scientificamerican.com/observations/decoherenc...