| Quantum information theory is an interdiscipline of quantum mechanics and information theory,which make an qualitative increase for the communi-cation security and computation speed,by applying the principle of quantum mechanics to information transmission and processing.In resent years,quantum information technology has makes important breakthrough for theory and ex-periment research.The quantum information processing(QIP)have many ap-plication such as quantum cryptography,quantum superdense coding,quantum teleportaton and one-way quantum computer.Entanglement,as an important quantum resource for tasks as superdense coding and high capacity quantum information processing.In this thesis,we will study input-output property of coupled-cavity,the generation and concertration of entanglement,based on the technology of cavity QED.The thesis contains the following works:1.we give a brief introduce of the single quantum-dot spin coupled double-sided optical microcavity,and make an analysis of the input-output relation of this kind of cavity.We get the rule of efficiencies and fidelities vary when the cavity field decay rate decreases.At the resonant frequency,we obtain the optimal parameters to attain the desired efficiencies and fidelities for this kind of system.By the use of our conclusions,one may quickly decide how to adjust the parameters to get a desired coupled cavity.2.Exploiting the optical excitation selection rules in graphene quantum dots,we investigate theoretically the entanglement generation process and en-tanglement concentration process of valley qubits.Our protocol shows that the graphene based quantum dots can be distributed in a maximally entangled state through the interaction with single photons.In our proposed scheme,the se-tups are simplified as only single photon detection is required.Our proposed scheme provides a fast,all-optical manipulation of on chip qubits which gives an effective way for quantum information processing in graphene based solid.qubits. |
PDF Full Text Request