Quantum Volume is a performance metric designed to evaluate the capabilities and error rates of quantum computers. It quantifies the maximum size of square quantum circuits that can be executed successfully on a given machine. The success of any benchmark is determined by specific criteria that define whether a given quantum computer has successfully executed a particular circuit. While the specific form of these circuits remains independent of the underlying architecture, compilers can optimize them to leverage the computer’s unique features. This allows for meaningful comparisons across different quantum architectures.
Quantum Volume is particularly significant because it addresses the inherent limitations of quantum computation. Although qubits are analogous to classical bits in some ways, their behavior diverges due to decoherence and error rates, making a small number of highly reliable qubits more valuable as a performance indicator than a larger number of noisy, unreliable qubits.
The concept of volumetric benchmarks further extends this line of reasoning by considering not just square circuits but also rectangular ones. This generalized approach allows for a deeper exploration of the trade-offs between circuit size (in terms of qubits) and depth. By decoupling these two dimensions, volumetric benchmarks provide a more nuanced understanding of how different quantum computers might perform under varying conditions.