Enlarge / Two generations of Google’s Sycamore processor. (credit: Google Quantum AI)

Today, Google announced a demonstration of quantum error correction on its next generation of quantum processors, Sycamore. The iteration on Sycamore isn’t dramatic—it’s the same number of qubits, just with better performance. And getting quantum error correction isn’t really the news—they’d managed to get it to work a couple of years ago.

Instead, the signs of progress are a bit more subtle. In earlier generations of processors, qubits were error-prone enough that adding more of them to an error-correction scheme caused problems that were larger than the gain in corrections. In this new iteration, adding more qubits and getting the error rate to go down is possible.

We can fix that

The functional unit of a quantum processor is a qubit, which is anything—an atom, an electron, a hunk of superconducting electronics—that can be used to store and manipulate a quantum state. The more qubits you have, the more capable the machine is. By the time you have access to several hundred, it’s thought that you can perform calculations that would be difficult to impossible to do on traditional computer hardware.