Fig. 4: Quantum Volume Circuit Construction and Measurement.
a Quantum volume circuits are constructed using SU(4) matrices. The number of qubits involved is referred to as the width, while the quantity of SU(4) matrices is known as the depth of the circuit. The quantum volume is determined by the maximum width and depth of a successful circuit. b To evaluate whether a circuit is successful, one must simulate it and sort the readout states based on their probabilities. States above the median are referred to as “heavy outputs''. If the state probability of all heavy outputs combined, within the 2σ deviation, from at least 100 trials exceeds 0.66, the circuit is considered successful. c The heavy output probability for a quantum volume measurement is simulated across all individual qubits and their connections. After a minimum of 100 trials, the measurements exceeded the threshold, achieving a maximum width and depth of m = 3, which corresponds to a quantum volume of 2m = 8.
