The Generation Of Cluster State Based On Faraday Rotation And Cavity Quantum Electrodynamics System

Quantum information science is a new subject which is a combination ofinformation science and quantum mechanics. Quantum information science mainlyincludes quantum communication and quantum computation. Quantum entanglementstate is the basic physical resource for the quantum communication. Especially, themulti-qubit entanglement states play the role of basic channel in the quantumcommunication. Such as quantum dense coding, quantum key distribution, quantumteleportation, quantum entanglement swapping and so on. Quantum entanglement statehas unique properties, which make quantum computer has many abilities, while theclassical computer has not，such as parallel computing ability and absolute secrecyability. In recent years, many theoretical schemes about the preparation of entanglementstate were presented and some implementation have been reported in experiment. Thepreparation of entanglement state in quantum cavity electrodynamics (cavity QED)system is a hot research topic, which is because of the quantum bits trapped in thecavity are considered as stationary qubits, and photons interact with system are used asflying qubits to carry quantum information. Combine the Faraday rotation mechanismand the input-output relation of the cavity, it proposes a scheme to achieve manyquantum information processes in a lowQ cavity. In this dissertation, the cluster state isgenerated through Faraday rotation in cavity QED system.This dissertation consists of five chapters. In the first chapter, we introduced theproject background. In the second chapter, some basic theories of quantum informationare introduced, including the quantum bit, main kinds of the quantum logic gate, thedefinition of quantum entanglement, serval kinds of entanglement states. In the thirdchapter, the basic theories of cavity QED and Faraday rotation mechanism areintroduced. Including the J-C model, the input-output relation of the cavity, Faradayrotation mechanism and how to control the Faraday rotation angle. The fourth chapter isour work. We show the preparation of the cluster state of N quantum dots and N photonsby adjusting the Faraday rotation angle in the appropriate values by some pertinentparameters, the Faraday rotation angle generated by the interaction betweem thesingle-photon and the cavity-embedded QD system. In this scheme, the cavity with noneed for the high-Q factors and unnecessary for strong coupling. Moreover, alloperations are done in the solid state system. In particular the preparation of the cluster of N photons is completed in a cavity-embedded QD system only, which makes full useof the physical resource. And it can further lower the difficulty of the experiment andprovide a good platform for future system integration. In the last chapter, made asummary for the work and made a prospect of the future about quantum informationscience.