Methods for mitigation and for characterization of logical errors in error corrected quantum processors

A quantum-computer implemented method for mitigating errors in a quantum circuit C including at least one error-corrected quantum logic operation G, the quantum-computer implemented method comprising:

• (a) providing a set of quantum error mitigation protocols {EM} including at least two quantum error mitigation protocols configured for mitigating errors in said quantum circuit C;
• (b) executing a plurality of shots, so as to obtain a plurality of mitigated circuit outcomes {o}, wherein:
• i) for at least one shot, the method includes executing said at least one error-corrected quantum logic operation G and measuring an associated at least one syndrome thereof, so as to obtain a syndrome measurement results vector {right arrow over (s)};
• ii) at least one shot is executed according to at least one quantum error mitigation protocol EM selected from said set of quantum error mitigation protocols {EM} based on said vector of syndrome measurement results {right arrow over (s)};
• (c) combining said mitigated circuit outcomes {o} so as to obtain an estimate ō of an outcome of an ideal version C0 of said quantum circuit C.