Implementation Of The Deterministic Quantum Cloning Machine

This paper is about the realization of deterministic quantum cloning. In the processing of realizing deterministic quantum cloning, using the characteristics of the deterministic quantum cloning, research and design the schemes of the multi-purpose quantum cloning machine which can perform the multiple processing of the quantum cloning. This paper has proposed several schemes for implementing multi-purpose quantum cloning machine including using a single system and using the combining system of the line optics and cavity quantum electric dynamics. The paper contains the following findings.1. Use the quantum logic gate for implementing multi-purpose quantum cloning machine. In the scheme, design the processing for achieving multi-purpose quantum cloning machine, which is built by some single-qubit logic gates and two-qubit logic gates. The scheme combines the single-qubit logic gates and multi-qubit logic gates to control some cloning parameters. By changing these parameters, the quantum cloning machine can achieve a variety of quantum cloning processing, such as:the optimal symmetric and asymmetric1→2universal quantum cloning, the optimal symmetric and asymmetric1→2phase-covariant quantum cloning and1→3economic phase-covariant quantum cloning. This processing is designed by using universal quantum gates, so the processing can be implemented in a single system, and can also be implemented in quantum network composed of a variety of systems.2. Use the Superconducting Quantum Interference devices(SQUIDs) resonance coupling to the cavity to achieve the multi-purpose quantum cloning machine. The paper proposes a scheme for implementing the multi-purpose quantum cloning machine. In the scheme, three SQUIDS are fixed in the cavity and coupled to the cavity, which can be driven by the laser pulses, respectively. Using the characteristics of the three SQUIDs, design the processing of the multi-purpose quantum cloning machine.3. Use the SQUIDs non-resonant coupling to the cavity to achieve the multi-purpose quantum cloning machine. The paper also proposes a scheme for realizing the multi-purpose quantum cloning machine. Similar to the above scheme, the three SQUIDs are fixed in the cavity and coupled to the cavity. The three SQUIDs can be manipulated by the laser pulses, respectively. Two SQUIDs can be controlled to non-resonant interaction with the cavity mode in step. This quantum cloning machine can also be used for different purposes, such as achieve universal quantum cloning and phase covariant quantum cloning by adjust the parameters.4. Use the ion trap system to design phase covariant quantum real state quantum cloning machine. The real state quantum cloning is another type of phase-covariant quantum cloning, which corresponds to the phase of the input state is already know, while the amplitude is unknown, the state corresponds to the meridian of the Bloch ball state. Compared to the universal quantum cloning, the real state quantum cloning and phase covariant quantum cloning both can obtain the copies with the better fidelity. As we all know, the ion trap system is an important physical system for manipulating quantum information processing. Consider three two-level ion is bound in a linear ion trap, this paper proposes the scheme can perform the phase covariant quantum cloning and real state quantum cloning experiments in this paper.5. Use the combination system of the linear optical components and cavity quantum electric dynamics to achieve the multi-purpose quantum cloning machine. The cavity quantum electric dynamics can transmit and exchange the quantum information between the photon and atoms. Use the characteristics to choose the leakage cavity system, which can provide the strong coupling interaction between photons and atoms, to complete the design of multi-purpose quantum cloning machine in quantum communication networks. In the scheme, the photons suitable for long-distance transmission were selected as the flying qubit, which can effectively ensure the quantum information less prone to distortion during transmission because of the photons are difficult to interact with the outside world. The atoms trapped in the unilateral leakage cavities are used for fixed qubit, which are distributed in each quantum computation node of the quantum network. Atoms are trapped in the cavities, making them isolated with the surrounding environments, this also ensures that its state can be stabilized for a long time to meet the requirements of quantum computation and quantum communication. In the design, simplicity, operability and versatility of the design also is considered, it can complete several quantum cloning processing including the universal quantum cloning machine and phase-covariant quantum cloning machine. In addition, another multi-purpose quantum cloning machine, which can copy quantum information both from photon qubits and atomic qubit, also be designed, by adjusting the parameters, the universal quantum cloning, the phase-covariant quantum cloning and the economic phase-covariant quantum cloning can be achieved.6. Realize the quantum telecloning in the separate cavities. The remote quantum operation can easily be performed in the separate cavities system, by using the characteristics, the paper design a scheme to achieve quantum telecloning machine. The scheme uses the combination system of the linear optical components and cavity quantum electric dynamics to prepare the quantum entanglement between the atom and the flight photon state. Then, the bell state measurement between the photon and a trapped atom with quantum information or the other photon with quantum information is performed. Lastly, the quantum telecloning can be achieved. In this scheme, based on the different quantum state of the qubit, which carries the different quantum information, the different quantum telecloning can be realized. In this system, the remote quantum operation can easily be performed, so, improving the probability of quantum telecloning is convenience.Overall, in the single system and the combining system of linear optics and cavity quantum electrodynamics, this paper proposes several schemes to implement the multi-purpose quantum cloning machine, and discusses the feasibility of the experiment.