Efficient local implementation of a nonlocal multi-party quantum Toffoli gate is considered. We present and demonstrate a scheme that can improve significantly the implementation of this nonlocal (N + 1)-party gate by harnessing N entangled pairs of qubits as quantum channels and a (N+1)-dimensional qudit as a catalyser. The quantum circuit that does the proposed implementation is built entirely of local single-body and two-body gates, and has only (2N + 1) two-body gates. The method that we describe is independent of the particular physical system used to encode quantum information and the way in which the elemental gates are realized.
展开▼
