Abstract: Circuit cutting enables the execution of large-scale quantum circuits on current quantum hardware. This technique partitions a large quantum circuit into sub-circuits, which are executed separately on hardware, and then reconstructs the overall computation result through classical post-processing of the sub-circuit outcomes. However, existing circuit cutting methods consider only a few specific quantum gates, resulting in expensive post-processing and sub-circuit execution overhead. This paper introduces a new circuit cutting scheme, named BlockCut, which enables cutting more general gate blocks composed of multiple quantum gates, surpassing existing methods restricted to only a few gate types. BlockCut is applicable to arbitrary n-qubit gate blocks and significantly reduces both the number of sub-circuits and the post-processing overhead. For the controlled Z (CZ) gate, BlockCut decomposes it into only 5 sub-circuits, whereas existing methods require at least 6 sub-circuits. Furthermore, BlockCut also supports co-optimization with hardware architectures. For a Toffoli gate distributed across multiple devices, BlockCut generates at most 10 device-local sub-circuits, while existing methods will generate up to 46,656 sub-circuits.

Key words: quantum computation, quantum compilation, quantum circuit cutting