SAN FRANCISCO (AP) — Google says it has achieved a breakthrough in quantum computing research.

It says an experimental quantum processor has completed a calculation in just a few minutes that would take a traditional supercomputer thousands of years.

The results of its study appear in the scientific journal Nature. Google says it has achieved quantum supremacy, which means the quantum computer did something a conventional computer could never do.

But competitor IBM is disputing that Google achieved the benchmark, saying Google underestimated the conventional supercomputer.

Quantum computing is an advanced computing technology that is still at a relatively early stage of development.