Table 2.

Single qubit characterization

Qubit	Freq.	Anharm.	T1	T2	EPG	EPG simul	Readout	Initialization	Reset	$P_{leak}^{m=10}$
(QF)	(GHz)	(MHz)	(μs)	(μs)	(%)	(%)	error (%)	error (%)	error (%)
1	4.664	−351.7	420.3	118.4	0.0102	0.0143	1.22	2.37	3.3	0.0884
2	4.799	−346.9	354.8	119.8	0.0128	0.0171	1.25	1.02	5.6	0.0203
3	4.862	−347.9	331.7	25.8	0.0096	0.0096*	0.75	1.27	5.4	0.0097
4	4.933	−345.9	124.8	77.3	0.0332	0.0315	0.47	0.52	2.0	0.0048
5	5.020	−343.9	131.7	215.5	0.0122	0.0145	0.79	1.23	1.2	0.0201
7	4.769	−347.1	424.5	59.7	0.0107	0.0212	0.47	0.22	3.3	0.1046
8	4.941	−344.3	249.4	228.8	0.0181	0.0310	0.46	0.67	1.1	0.0164
9	5.219	−339.4	271.7	316.0	0.0069	0.0287	1.28	1.89	1.7	0.0490
10	4.863	−347.1	357.0	72.0	0.0184	0.0207	0.30	0.53	1.8	0.0106
11	5.128	−341.4	283.8	188.8	0.0199	0.0217	1.38	2.82	2.6	0.0136
12	4.933	−344.8	280.9	353.0	0.0190	0.0367	0.38	0.26	1.2	0.0182
13	5.006	−356.5	349.8	345.0	0.0168	0.0410	0.10	0.74	0.9	0.0898
14	4.839	−377.2	399.3	99.7	0.0157	0.0694	1.22	3.67	4.6	0.0277
15	4.991	−368.8	226.6	217.4	0.0352	0.0473	0.37	1.48	3.2	0.0172
16	5.107	−342.0	259.8	209.2	0.0100	0.0280	0.70	0.88	1.2	0.0200
17	5.173	−339.3	234.4	311.7	0.0207	0.0324	0.65	0.71	1.6	0.0204
18	5.103	−339.9	195.5	34.7	0.0138	0.0118	0.26	0.40	1.2	0.0220
19	4.819	−376.7	319.6	167.6	0.0311	0.0485	2.15	8.87	7.2	0.0128
21	4.890	−345.8	278.1	308.0	0.0131	0.0143	0.53	0.77	0.7	0.0086
22	4.955	−344.2	206.9	132.4	0.0105	0.0177	0.62	1.30	1.8	0.0434
23	5.045	−341.8	278.3	145.0	0.0118	0.0118*	0.28	0.34	0.8	0.0192
24	5.136	−341.1	258.7	14.6	0.0147	0.0169	0.36	0.28	2.6	0.0096
25	5.027	−341.7	364.1	327.5	0.0160	0.0265	0.42	0.45	0.8	0.0164
Mean	4.966	−348.50	287.0	177.7	0.0165	0.0266	0.713	1.42	2.43	0.0288
Std.	0.139	10.8	79.9	107.0	0.0074	0.0140	0.48	1.81	1.73	0.0273

Single qubit device parameters, using IBM-Falcon qubit numbering presented in Fig. 4a for ibm_peekskill. Single qubit error per gate (EPG) from randomized benchmarking (RB) with all coupled qubits idled. In contrast, simultaneous single qubit EPG (EPG simul) is obtained by performing one qubit RB concurrently with two qubit RB on neighboring gates to more realistically approximate simultaneous application of gates in stabilizers (asterisked values are isolated EPG, as these qubits are not captured in this scheme). To separate readout from initialization and reset errors, readout error is extracted from overlap of gaussian fits to ground and excited state histograms. The initialization sequence for the data presented in this paper used 6 rounds of conditional reset, with a single Xπ_e−f after 3 rounds to help reset f-state population. The initialization error is benchmarked with this sequence applied simultaneously on all qubits. Reset error is the average non-zero state population after a single round of conditional reset (simultaneous on all qubits) after preparing all qubits on with an X_π/2, to capture mid-circuit reset needed for each stabilizer round. Probability of leakage after 10 measurements, see Eq. (15), is from benchmarking pulse-sequence in Fig. 5a.