Practical quantum error mitigation effect by randomized compiling and zero-noise extrapolation for trapped-ion quantum hardware

A synergistic combination of randomized compilation (RC) and zero-noise extrapolation (ZNE) is known to significantly suppress computational errors induced by various types of coherent noise. Although numerical simulations suggest the effectiveness of the scheme, its real-hardware performance requires investigation. Here, we implemented this error mitigation scheme on trapped-ion quantum hardware to perform quantum chemical calculations. While this scheme yielded error-mitigated values closer to the exact values, residual errors persisted. We analyzed the effects of experimental parameters—extrapolation method, number of randomized circuits, and measurement count—on the results.