[LouisSayers]

Anyone care to give their take on Quantum Computing?

Does it have practical application? Are we actually progressing towards something or are research papers just a way to get the next grant in order to continue playing with Quantum?

[commandersaki]

I posted this as a submission that didn't really garner interest but from the cryptanalysis angle it is a boondoggle, here's a video of Peter Gutmann presenting his take: https://www.youtube.com/watch?v=xa4Ok7WNFHY

[LouisSayers]

Awesome, thanks for that! That does confirm some of my suspicions...

He lives just a few hours from me as well.

[everfrustrated]

Quantum makes the fusion folks look fast

[johnsmith1840]

Likely will work but it doesn't have a "killer app" yet so less funding than needed.

My understanding is that programming it is like building a house of cards so that when it falls the pile at the end is an answer. Very different way of thinking and there's no nice abstraction layers.

Needs more reliability and and something equivalent to a compiler and C programming.

[skybrian]

> the main known applications of quantum computers remain (1) the simulation of quantum physics and chemistry themselves, (2) breaking a lot of currently deployed cryptography, and (3) eventually, achieving some modest benefits for optimization, machine learning, and other areas (but it will probably be a while before those modest benefits win out in practice).

...

> 2025 was clearly a year that met or exceeded my expectations on hardware, with multiple platforms now boasting >99.9% fidelity two-qubit gates, at or above the theoretical threshold for fault-tolerance. This year updated me in favor of taking more seriously the aggressive pronouncements—the “roadmaps”—of Google, Quantinuum, QuEra, PsiQuantum, and other companies about where they could be in 2028 or 2029.

...

> at some point, the people doing detailed estimates of how many physical qubits and gates it’ll take to break actually deployed cryptosystems using Shor’s algorithm are going to stop publishing those estimates, if for no other reason than the risk of giving too much information to adversaries. Indeed, for all we know, that point may have been passed already. This is the clearest warning that I can offer in public right now about the urgency of migrating to post-quantum cryptosystems, a process that I’m grateful is already underway.

https://scottaaronson.blog/?p=9425

[tim333]

I'm skeptical. Wake me when they can factor a number bigger than 31.