Quantum Volume

As we build larger quantum computing devices capable of performing more complicated algorithms, it is important to quantify their power. The origin of a quantum computer’s power is already subtle, and a quantum computer’s performance depends on many factors that can make assessing its power challenging. These factors include: 1. The number of physical qubits; 2. The number of gates that can be applied before errors make the device behave essentially classically; 3. The connectivity of the device; 4. The number of operations that can be run in parallel. Here we propose an architecture-neutral metric, the quantum volume, to summarize performance against these factors. The quantum volume measures the useful amount of quantum computing done by a device in space and time. Table 1 summarizes predicted quantum volumes for potential near-term devices.