CONTENTS -- Preface -- Liquid-state NMR Quantum Computer: Working Principle and Some Examples -- 1. Introduction -- 2. Principle of NMR -- 2.1. Vector model -- 2.1.1. Magnetic moment -- 2.1.2. Precession -- 2.1.3. Rotating magnetic .eld -- 2.1.4. Bloch equation -- 2.1.5. Spin echo -- 2.1.6. NMR equipment and signal detection -- 2.2. Quantum mechanical view -- 2.2.1. Magnetic moment -- 2.2.2. Precession -- 2.2.3. Rotating magnetic .eld -- 2.2.4. Bloch equation -- 2.2.5. Spin echo -- 2.2.6. NMR equipment and signal detection -- 3. Principle of Liquid-State NMR Quantum Computer -- 3.1. Two-qubit Hamiltonian -- 3.2. One-qubit gates -- 3.3. Two-qubit gates -- 3.4. Non-unitary operations -- 3.4.1. Temporal averaging -- 3.4.2. Spatial averaging -- 3.5. Separability -- 4. Quantum Computation -- 4.1. Quantum channel -- 4.1.1. Quantum channel and entanglement .delity -- 4.1.2. Phase .ip channel -- 4.1.3. Quantum process tomography -- 4.2. Generation and suppression of artificial decoherence -- 4.2.1. Decoherence -- 4.2.2. Phase flip channel -- 4.2.3. Suppressing decoherence by the bang-bang control -- 4.2.4. Arti.cial environment -- 4.2.5. Phase decoherence in a quantum memory -- 4.2.6. Simulation of phase decoherence in a quantum memory -- 4.3. Quantum teleportation -- 4.3.1. Theory -- 4.3.2. Quantum circuit -- 4.3.3. Sample and spectrometer -- 4.3.4. Hamiltonian and detector -- 4.3.5. Pulse sequence -- 4.3.6. Experiments -- 4.3.7. Results -- 5. Conclusions -- Acknowledgments -- References -- Flux qubits, Tunable Coupling and Beyond -- References -- Josephson Phase Qubits, and Quantum Communication via a Resonant Cavity -- References -- Quantum Computing Using Pulse-based Electron-nuclear Double Resonance (ENDOR): Molecular Spin-qubits -- 1. Introduction -- 1.1. General Introduction -- 1.2. An Electron Spin as an Inherent Matter Spin-Qubit.

1.3. Advantages of Photon Qubits Compared with Matter Spin-Qubits in Terms of Enabling Technology -- 2. A Short Course of Pulsed ENDOR for Non-Specialists -- 2.1. Gyromagnetic Ratios of an Electron Spin and Nuclear Spin: Bohr Magneton for Electrons vs. Nuclear Magneton -- 2.2. What is Electron Spin Resonance/Electron Paramagnetic Resonance (ESR/EPR)? : A Basis for ESR/EPR Spectroscopy -- 2.3. Spectral Density of Electron Magnetic Resonance Transitions: High Resolution and High Sensitivity by Quantum Transformation in ENDOR Spectroscopy -- 2.4. Fourier-Transform ESR/ENDOR Spectroscopy: Pulse-Based ESR/ENDOR as Enabling Spin Technology -- 2.5. A Basis of Spin Manipulation Technology for QC/QIP in Pulse Electron Magnetic Resonance -- 2.6. An Electron-Spin Echo of Spin Packets Generated by Three-Pulse Sequence in Electron Magnetic Resonance -- 2.7. A Basis for Pulse-Based ENDOR Spin Technology: Two Types of Electron-Spin-Echo Detected ENDOR Spectroscopy -- 2.8. Generation of A Pseudo Pure State for Electron-Nuclear Spin-Qubit Systems by Pulse-Based ENDOR Spin Technology -- 2.9. Generation and Identification of Quantum Entanglement between An Electron and One Nuclear Spin-Qubit by Pulse-Based ENDOR Spin Technology -- 2.10. Inter-Conversion of Entangled States by Pulse ENDOR Technique -- 2.11. TPPI Detection of the Entanglement between Electron-Nuclear Hybrid Spin-Qubits by Pulse ENDOR Technique -- 3. Implementation of Molecular-Spin Based QC/QIP by the Use of Pulse ENDOR Spin Technology -- 3.1. Why Is Molecular Spin-Qubit Based QC/QIP by Using Pulse ENDOR Spin Technology Emerging? -- 3.1.1. Pseudo-pure states and quantum entanglements -- 3.1.2. Molecular spin-qubit ENDOR based quantum computers -- 3.1.3. Preparation of a molecular entity for QC-ENDOR: The simplest case.

3.1.4. Implementation of super dense coding by pulsed QC-ENDOR and a direct detection of the spinor of the spin-1/2 proton -- 3.2. TPPI Detection and Inter-Conversion of the Bell States by Pulse ENDOR -- 3.3. The First Direct Detection of Spinor of an Electron Spin-Qubit by Phase Manipulation -- 3.4. Tri-partite Electron-Spin Nuclear-Qubits Experiments -- Identification of Separable States Decomposed into the Bi-partite Entanglements -- 4. Development of Coherent-Dual ELDOR Technique for Molecular Electron Spin-Qubits Based Quantum Computers -- 4.1. Electron Spin Manipulation Technology beyond Pulse ENDOR: CD-ELDOR Technique -- 4.2. Materials Challenge for Biradical Qubits with Small Spin-Orbit Interactions: g-Engineering Approach to Molecular Design -- 5. Scalable Molecular-Spin Based Electron Spin-Qubits: Spin-Qubits Systems with 1D Periodic Spin Structure Proposed by Lloyd -- 6. Conclusions -- Acknowledgments -- References -- Fullerene C60: A Possible Molecular Quantum Computer -- 1. Introduction -- 2. Fullerenes and Endohedral Fullerenes -- 2.1. Historical Overview -- 2.2. Physical Properties of Fullerenes -- 2.3. Putting Atoms inside Forming Endohedral Fullerenes -- 2.4. Detection of the Endohedrals -- 2.5. The Yields of the Endohedrals -- 2.6. Concentration and Purification -- 3. Experimental Approaches to QC/QIP -- 3.1. Necessary Properties for QC/QIP -- 3.2. From NMR to ESR -- 3.3. Nitrogen Atom in a C60 Cage -- 3.4. Proposal and Implementation of Fullerene Quantum Computer -- 3.5. The ESR and ENDOR Experiments -- 4. Production of N@C60 at Kindai -- Acknowledgments -- References -- Molecular Magnets for Quantum Computation -- 1. Introduction -- 2. Recent progress in application of molecular magnets to quantum computation -- 2.1. Mn12 SMM -- 2.2. [Mn4]2 as a dimer of SMM -- 2.3. Antiferromagnetic rings of [Cr7Ni] -- 3. Summary -- References.

Errors in a Plausible Scheme of Quantum Gates in Kane's Model -- 1. Introduction -- 2. Kane's model -- 2.1. Overview -- 2.2. Readout of a qubit -- 2.3. Requisite techniques for the fabrication -- 3. Hamiltonian and computation bases -- 3.1. Hamiltonian -- 3.2. Computation bases -- 3.3. Is a nuclear spin a qubit? -- 4. Spin-flip operations -- 4.1. Controlling processes -- 4.2. Schrödinger equation in the second step -- 4.3. Errors in spin-flip operations -- 5. Suppression of leakage errors -- 5.1. Model -- 5.2. Determination of parameters for leakage elimination -- 5.3. Leakage free quantum gates -- 5.4. Leakage elimination of spin-flip operations in Kane's model -- 6. Summary -- Acknowledgments -- References -- Yet Another Formulation for Quantum Simultaneous Noncooperative Bimatrix Games -- 1. Introduction -- 2. Conventional Classical and Quantum Simultaneous Noncooperative Bimatrix Games -- 2.1. Classical simultaneous noncooperative game -- 2.2. Quantum simultaneous noncooperative game -- 3. Is entanglement or nonclassical correlation an important resource? -- 3.1. Strategically equivalent games without using entanglement -- 3.2. Solving the PD dilemma with fancy observables -- 4. Overview of the Metagame Theory -- 5. Quantum Metagame -- 5.1. From quantum PD to quantum meta-PD -- 5.2. From quantum Samaritan's Dilemma to quantum meta-Samaritan's Dilemma -- 6. Discussions -- 7. Conclusion -- References -- Continuous-variable Teleportation of Single-photon States and an Accidental Cloning of a Photonic Qubit in Two-channel Teleportation -- 1. Introduction -- 2. Transfer operator -- 3. Single-photon state teleportation -- 4. Application to a single-photon polarization -- 5. Transfer of polarization by two-mode CV teleportation -- 6. CV teleportation of a single-photon polarization qubit -- 7. Cloning fidelity of the N-photon output -- 8. Conclusions.

References.