Pre-processing of quantum circuit mapping based on circuit partitioning and unitary matrix decomposition

Quantum computing is currently in the era of Noisy-Intermediate-Scale Quantum (NISQ), where superconducting quantum chips can only support two-qubit gates between adjacent physical qubits. This constraint necessitates the insertion of SWAP gates during circuit mapping to ensure that the nearest neighbor requirements are met on actual quantum computing devices. In this work, based on the circuit partitioning and unitary matrix decomposition mechanism, an equivalent transformation form of quantum circuit is given to reduce the number of two-qubit gates in the target quantum circuit. Experimental results demonstrate that the decomposed equivalent circuits have a shorter depth, with an average optimization rate of 18.41%. Our proposed optimization method effectively reduces the number of two-qubit gates in quantum circuits, enhancing the efficiency of mapping on NISQ devices.