Partial randomized benchmarking
Abstract
In randomized benchmarking of quantum logical gates, partial twirling can be used for simpler implementation, better scaling, and higher accuracy and reliability. For instance, for twoqubit gates, singlequbit twirling is easier to realize than full averaging. We analyze such simplified, partial twirling and demonstrate that, unlike for the standard randomized benchmarking, the measured decay of fidelity is a linear combination of exponentials with different decay rates (3 for two qubits and singlebit twirling). The evolution with the sequence length is governed by an iteration matrix, whose spectrum gives the decay rates. For generic twoqubit gates one slowest exponential dominates and characterizes gate errors in three channels. Its decay rate is close, but different from that in the standard randomized benchmarking, and we find the leading correction. Using relations to the local invariants of twoqubit gates we identify all exceptional gates with several slow exponentials and analyze possibilities to extract their decay rates from the measured curves.
 Publication:

Scientific Reports
 Pub Date:
 June 2022
 DOI:
 10.1038/s4159802213813x
 arXiv:
 arXiv:2111.04192
 Bibcode:
 2022NatSR..1210129D
 Keywords:

 Quantum Physics
 EPrint:
 Sci. Reports 12, 10129 (2022)