A quantum computer with great enough complexity—for instance, enough components known as quantum bits or “qubits"—could in theory achieve a "quantum advantage" allowing it to find the answers to problems no classical computer could ever solve. In principle, a quantum computer with 300 qubits could perform more calculations in an instant than there are atoms in the visible universe.
In 2019, Google argued it displayed such "quantum primacy" with its 53-qubit Sycamore processor, carrying out a calculation in 200 seconds that the company estimated would take Summit, the world's most powerful supercomputer at that time, 10,000 years. However, IBM researchers later called that quantum advantage claim in question, arguing that with better classical algorithms, Summit could actually solve that problem in 2.5 days.
