Table 2.

Summary of the achieved success probabilities for the implemented circuits, in percentages

Connectivity	Star shaped			Fully connected
Hardware	Superconducting			Ion trap
Success probability/%	Obs	Rand	Sys	Obs	Rand	Sys
Margolus	74.1(7)	82	75	90.1(2)	91	81
Toffoli	52.6(8)	78	59	85.0(2)	89	78
Bernstein–Vazirani	72.8(5)	80	74	85.1(1)	90	77
Hidden shift	35.1(6)	75	52	77.1(2)	86	57

The observed probabilities (“Obs”) are tabulated alongside two simple error propagation models given the gate number N and the individual gate and readout errors of the two systems encapsulated in the parameters ϵ_g and ϵ_M, respectively (main text). The first stimate assumes random (“Rand”) error propagation with overall error ${\left(1-{ϵ}_g\right)}^{\sqrt{N}}$ whereas the second one is based on systematic (“Sys”) coherent over- or underrotations with overall error (1 − ϵ_g)^N, where N is the number of gates. The readout error for M qubits is (1 − ϵ_M)^M in both cases.