Recent announcement in quantum computing progress are using a metric known as Quantum Volume, not simply the number of qubits. The more complex metric is perhaps not as obvious and not as headline grabbing. But what does it actually mean? Both Honeywell and IBM are using Quantum Volume despite IBM inventing the term.
The recent announcement that IBM has achieved a Quantum Volume of 64 comes hot on the heels of the announcement from Honeywell that also achieved a quantum volume of 64. In a bit of a competitive Quantum Volume jousting, Honeywell is using IBM’s measure of quantum volume to beat it to the punch to getting a quantum volume of 64. But for many, other than taking the volume as a back-box measure is not sufficient, they want to understand what it actually means. Rather than explain it here, the Qiskit blog has a well written article on Quantum Volume.