Even if I share the security concerns at this point: Improved gate fidelity is a necessary but not sufficient condition for building a scalable, fault-tolerant quantum computer. As physicist Mikhail Dyakonov has cautioned, there are profound theoretical and practical obstacles that remain unresolved. Issues such as error correction, decoherence, and the physical scalability of qubit systems pose significant challenges. The threshold theorem suggests that below a certain error rate, quantum error correction can, in theory, make quantum computation feasible. However, the overhead in terms of additional qubits and operations required for error correction is enormous. Peter Shor himself has acknowledged that the resources needed for practical quantum error correction are daunting with current technology.
Aaronson's enthusiasm is reminiscent of earlier hype cycles in technology. For instance, his optimistic views on artificial intelligence did not always engage deeply with how general reasoning abilities were being achieved or demonstrated! Fully on hype train there. This pattern raises concerns about the balance between genuine technological progress and premature excitement that may not fully account for underlying complexities. Other experts advocate for a more measured perspective. Gil Kalai, for example, has been a vocal skeptic about the scalability of quantum computers, emphasizing that quantum error rates might not be reducible to the levels required for practical machines. His arguments suggest that noise and decoherence could be fundamental barriers, not just engineering challenges to be overcome with incremental improvements. On Friday, September 27, 2024 at 6:36:21 PM UTC+2 John Clark wrote: > *It looks like conventional Superintelligence is not the only revolution > that's going to make our world almost unrecognizable before 2030 or so. > Scott Aaronson has been working in the field of quantum computing since the > late 1990s but he has always strongly objected to the hype surrounding > them, for years he said practical quantum computers might not be possible > and even if they were he didn't expect to see one in his lifetime. But I > noticed Aaronson's tone started to change about two years ago and he now > thinks we will either have a practical quantum computer very soon or we > will discover something new and fundamental about quantum mechanics that > renders such a thing impossible. He says "Let’s test quantum mechanics in > this new regime. And if, instead of building a QC, we have to settle for > “merely” overthrowing quantum mechanics and opening up a new era in > physics—well then, I guess we’ll have to find some way to live with that".* > > *The following are more quotations from Aaronson's latest blog but I think > it would be well worth your time to read the entire thing: * > > *"**If someone asks me why I’m now so optimistic, the core of the > argument is 2-qubit gate fidelities. We’ve known for years that, at least > on paper, quantum fault-tolerance becomes a net win (that is, you > sustainably correct errors faster than you introduce new ones) once you > have physical 2-qubit gates that are ~99.99% reliable. The problem has > “merely” been how far we were from that. When I entered the field, in the > late 1990s, it would’ve been like a Science or Nature paper to do a 2-qubit > gate with 50% fidelity. But then at some point the 50% became 90%, became > 95%, became 99%, and within the past year, multiple groups have reported > 99.9%. So, if you just plot the log *of the infidelity* as a function *of > year* and stare at it—yeah, you’d feel pretty optimistic about the next > decade too!* > *Or pessimistic, as the case may be! To any of you who are worried about > post-quantum cryptography—by now I’m so used to delivering a message of, > maybe, eventually, someone will need to start thinking about migrating from > RSA and Diffie-Hellman and elliptic curve crypto* [which bitcoin uses]* to > lattice-based crypto, or other systems that could plausibly withstand > quantum attack. I think today that message needs to change. I think today > the message needs to be: yes, unequivocally, worry about this now. Have a > plan.*" > > *Quantum Computing: Between Hope and Hype* > <https://scottaaronson.blog/?p=8329> > > John K Clark See what's on my new list at Extropolis > <https://groups.google.com/g/extropolis> > ecc > > > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/8b504eea-4390-444b-8be2-e096d1872bc3n%40googlegroups.com.
