Fig. 2. Fidelity estimates on 50 qubits.

Top left: ideal results from noise-free simulation, raw fidelity estimates using only M3 readout error mitigation, and the $\overline{\mathrm{CVaR}}$ upper bounds (UB) and corresponding 95% confidence intervals (shaded area). Bottom left: difference between $\overline{\mathrm{CVaR}}$ upper bounds and ideal noise-free results and corresponding 95% confidence intervals (shaded area). Top right: same as top left but with fitted $\overline{\mathrm{CVaR}}$ values. Bottom right: same as bottom left but for fitted $\overline{\mathrm{CVaR}}$ values.

Source data.