Quantum cloning machines for equatorial qubits
Heng Fan, Keiji Matsumoto, Xiang‐Bin Wang, Miki Wadati · Physical Review A · 2001
Quantum cloning machines for equatorial qubits are studied. For the case of a one to two phase-covariant quantum cloning machine, we present the networks consisting of quantum gates to realize the quantum cloning transformations. The copied equatorial qubits are shown to be separable by using Peres-Horodecki criterion. The optimal one to M phase-covariant quantum cloning transformations are given.