Circuit structure-preserving error mitigation for High-Fidelity Quantum Simulations

Developing methods to accurately characterize and mitigate the impact of noise is crucial for enhancing the fidelity of quantum simulations on Noisy Intermediate-Scale Quantum (NISQ) devices. In this work, we present a circuit structure-preserving error mitigation framework for parameterized quantum circuits. A key advantage of our approach lies in its ability to retain the original circuit architecture while effectively characterizing and mitigating gate errors, enabling robust and high-fidelity simulations. This makes it particularly well suited for small-scale circuits that require repeated execution at large sampling rates. To demonstrate the effectiveness of our method, we perform variational quantum simulations of a non-Hermitian ferromagnetic transverse-field Ising chain on IBM Quantum processors. The mitigated result shows excellent agreement with exact theoretical predictions across a range of noise levels. Our strategy offers a practical solution for addressing gate-induced errors and significantly broadens the scope of feasible quantum simulations on current quantum hardware.