Efficient Implementation of Multi-Controlled Quantum Gates

Understand

We present an implementation of multi-controlled quantum gates which provides significant reductions of cost compared to state-of-the-art methods.

• The operator applied on the target qubit is a unitary, special unitary, or the Pauli X operator (Multi-Controlled Toffoli), and requires one clean ancilla, no ancilla, and one dirty ancilla, respectively.
• We generalize our methods for any number of target qubits, and provide further cost reductions if additional ancilla qubits are available.
• For each type of multi-controlled gate, we provide implementations for unrestricted (all-to-all) connectivity and for linear-nearest-neighbor.