FCM: A Fusion-aware Wire Cutting Approach for Measurement-based Quantum Computing

Measurement-based quantum computing (MBQC) is a promising quantum computing paradigm that carries out computation through one-way measurements on entangled photon qubits. Practical photonic hardware first generates a 2D mesh of resource states with each being a small number of entangled photon qubits and then exploits fusion operations to connect resource states to scale up the computation. Given that the fusion operation is highly error-prone, it is important to reduce the number of fusions for an MBQC circuit.

In this paper, we propose FCM, a fusion-aware scheme that exploits wire cutting to improve the fidelity of MBQC. By cutting a large MBQC circuit into several smaller subcircuits, FCM effectively reduces the number of fusions in each subcircuit and thus improves the computation fidelity. Given circuit cutting requires classical post-processing to combine the results of subcircuits, FCM strives to achieve the best cutting strategy under different settings. Experimental evaluation of representative benchmarks demonstrates that, when cutting a large circuit to two subcircuits, FCM reduces the maximum number of fusions of all subcircuits by 59.6% on average (up to 69.1%).