Error mitigation on global entangling gates with trapped ions

Quantum error mitigation is an algorithmic method to improve the accuracy of output results of a quantum circuit without quantum error corrections that requires plenty of quantum resource overheads. It has been extensively explored in noisy-intermediate-scale-quantum (NISQ) systems. Quantum error mitigation, in particular, a probabilistic error cancelation method has been demonstrated for two-qubit gates and but it has not been applied to more than two-qubit gates because of the difficulty in characterizing quantum processes of multi-qubit gates. Recently, a few methods for characterizing multi-qubit operations and mitigating errors have been proposed with the assumption of a sparse error model or matrix product representation. We apply the quantum error mitigation methods to global entangling gates [1] that make all-to-all connections and provide efficient quantum computations. Our finding can be an important means for extending systematic error-mitigation schemes toward practical quantum advantages.