IBM quantum computer does in 19 seconds what could take a supercomputer 110 years

[Riddler]

ScienceAlert has a write up on a new quantum advantage claim using IBM hardware. A team led by Tigran Sedrakyan from BlueQubit used IBM's Nighthawk r2, a 120 qubit superconducting processor available through the cloud, to run a random circuit sampling task. Using 61 qubits across 36 cycles, it produced one million samples in just 19 seconds. The researchers estimate the same job would take around 110 years on Frontier, which was the world's fastest supercomputer before 2024

The authors describe it as the first demonstration of quantum advantage for vanilla random circuit sampling on a commercially and broadly accessible quantum processor. That last part is the point. Previous advantage claims came from custom lab setups, while this ran on a machine anyone with cloud access could in principle use, with standard workflows and no special calibration

There are big caveats though. The 110 year figure comes from one particular classical method, tensor network contraction, which put the classical cost at around 1.2 times 10 to the 27 operations. That is not a fundamental limit. Classical researchers have a long history of finding clever shortcuts that shrink these estimates dramatically, as happened with Google's 2019 claim. The paper is also a preprint on arXiv and has not been peer reviewed

To their credit, the team has released their circuits, samples and code so others can check the result. That is exactly how it should be done. If classical researchers want to knock the estimate down, they have everything they need to try

Random circuit sampling is also not a useful task in itself. It is essentially a benchmark designed to be hard for classical computers, rather than something that solves a real problem. So this is a milestone in the arms race between quantum and classical computing, not a sign that quantum computers are about to replace supercomputers. How long before we see advantage on something practical?

IBM's Quantum Computer Completes in 19 Seconds What Could Take a Supercomputer a Centurywww.sciencealert.com