Teleportation Scheme Implementing the Universal Optimal Quantum Cloning Machine and the Universal NOT Gate

By a significant modification of the standard protocol of quantum state teleportation, two processes “forbidden” by quantum mechanics in their exact form, the universal NOT gate and the universal optimal quantum cloning machine, have been implemented contextually and optimally by a fully linear method. In particular, the first experimental demonstration of the tele-UNOT gate, a novel quantum information protocol, has been reported. The experimental results are found in full agreement with theory.

Figure 1

General scheme for the simultaneous realization of the tele-UNOT gate and of the probabilistic universal quantum cloning machine (UOQCM).

Figure 2

Setup for the optical implementation of the tele-UNOT gate and the probabilistic UOQCM. The measurement setup used for the verification of the cloning experiment is reported in the inset (b).

Figure 3

Experimental results of the tele-UNOT gate and the UOQCM for three input qubits. Filled squares: plots corresponding to the “correct” polarization. Open triangles: plots corresponding to the “wrong” polarization. The solid line represents the best Gaussian fit expressing the correct polarization.