An ordinary laptop just solved a problem everyone assumed needed a quantum computer

[AlexaBliss]

Researchers used tensor networks to compress the overwhelming wave function created by hundreds of entangled qubits, and solved a problem on relatively modest classical hardware that had previously been described as impossible without a quantum computer

This is not the first time a classical algorithm has clawed back ground that quantum computing was supposedly going to own outright, but it is a good reminder that quantum advantage claims need to be checked against the best classical methods available at the time, not against naive brute force

The tensor network approach works by finding structure in the entanglement pattern that lets you represent the system far more compactly than a full exponential state vector would require, which is exactly the kind of mathematical trick that keeps eating into quantum's claimed advantage

For people tracking quantum computing progress this is a useful corrective, the goalposts for genuine quantum advantage keep moving because classical algorithms keep getting smarter about compression and approximation, it is not that quantum hardware regressed, it is that the classical bar rose

None of this means quantum computing is not making real progress elsewhere, but it does mean any specific advantage claim has a shelf life until someone finds the classical shortcut, and that shelf life has been getting shorter not longer over the past few years

An ordinary laptop solved a problem thought to require a quantum computerwww.sciencedaily.com