Quantum volume is just a marketing metric with no scientific meaning

Quantum volume is a rigorous composite metric defined in a peer-reviewed paper (Cross et al., 2019). It measures the largest random square circuit a device can execute with greater than 2/3 probability of success. A circuit of depth d on d qubits tests qubit count, connectivity, gate fidelity, and coherence time simultaneously. QV doubles only when all four improve together. IonQ and Quantinuum trapped-ion devices routinely score higher QV than IBM superconducting devices despite having far fewer qubits — which proves it is not an IBM-favoring metric.

This concept requires either mathematical proof or hardware-scale experiments beyond what a browser simulator can demonstrate. See the research notes for the canonical references.