P-computers can solve spin-glass problems faster than quantum systems (opens in new tab)

The submission is an ad.

University press releases should not be posted on HN. a press release is just a published paper + PR spin. If the PR spin were true, it would be in the paper. Just link to the paper.

https://www.nature.com/articles/s41467-025-64235-y

Title: "Pushing the boundary of quantum advantage in hard combinatorial optimization with probabilistic computers"

Abstract: "Adaptive parallel tempering [...] scales more favorably and outperforms simulated quantum annealing"

HN title should be changed to match the paper title or abstract.

The communication is in a superstate that has yet to collapse.

Just remains to be seen whether they can maintain capitalization long enough to find PMF

The answer should be no right? I think BPP is expected to be equal to P and BQP to be not equal to P.

P-computers is just another name for legume-computers, which are great for bean-counting, and are deployed in pods.

Probably against guidelines, but made me smile, so there's your upvote sir. Tastefully obscure yet crass :)

The power of quantum computing is constructing the solution to a problem out of an interference pattern. Classical probabilities don’t interfere, but quantum probabilities do. Loosely, quantum probabilities can be constructed to cancel, since their amplitudes can be negative.

Shor’s algorithm works on the quantum Fourier transform. The quantum Fourier transform works because you can pick a frequency out of a signal using a “test wave.” The test wave can select out the amplitude of interest because the information of the test wave constructively interferes, whereas every other frequency cancels. This is the interference effect that can only happen with complex/negative probability amplitudes.

That's a cool thought! For those who may not know, Shor's algorithm is fundamentally quantum because it relies on the interference of probability amplitudes, which can be both positive and negative. It could not be directly implemented on a p-computer because you could only simulate this interference, which removes the exponential advantage.

It's possible that an entirely different approach is made possible by p-computers, but this would be tricky to find. Furthermore, it seems that the main advantage of p-computers is sampling from a Boltzmann-like distribution, and I'm not aware that this is the bottleneck in any known factorisation algorithm.

A direct equivalent, no, as stated in the introduction.

"Notably, while probabilistic computers can emulate quantum interference with polynomial resources, their convergence is in general believed to require exponential time [10]. This challenge is known as the signproblem in Monte Carlo algorithms [11]."

I doubt it. Shor's algorithm relies on the quantum Fourier transform, which requires the complex phase information encoded in the quantum wavefunctions. The quantum probability norm (L2) accounts for interference between the complex amplitudes of these wavefunctions; the classical L1 probability norm does not.

The paper compares p-computers with D-Wave's quantum annealing machine, which is limited to only solving certain problems (as opposed to universal QC such as Google or IonQ's, that could in theory implement Shor's)