  The number of qubits in current quantum computers is a major restriction on
their wider application. To address this issue, Ying conceived of using two or
more small-capacity quantum computers to produce a larger-capacity quantum
computing system by quantum parallel programming ([M. S. Ying, Morgan-Kaufmann,
2016]). In doing so, the main obstacle is separating the quantum gates in the
whole circuit to produce a tensor product of the local gates. In this study, we
theoretically analyse the (sufficient and necessary) separability conditions of
multipartite quantum gates in finite or infinite dimensional systems. We then
conduct separation experiments with n-qubit quantum gates on IBM quantum
computers using QSI software.
