Quantum Error Mitigation via Quantum-Noise-Effect Circuit Groups

In this work, we develop our quantum-error-mitigation (QEM) scheme for quantum computational errors induced by quantum noise effects (decoherence effects) with using ensembles of quantum circuits called “quantum-noise-effect circuit groups”, which enable us to estimate the quantum computational errors. We discuss both theoretically and numerically the effectiveness of our QEM scheme and show that it has three advantages, (i) it can be performed with any type of quantum device, (ii) it can be applied to any type of quantum algorithm and any quantum noise effects with arbitrary strengths, (iii) the computational cost (practically) scales polynomial with respect to the product of the number of qubits and the depth of a quantum algorithm.