Preface |
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vii | |
Introduction |
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1 | (8) |
1 Introduction to classical computation |
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9 | (46) |
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9 | (7) |
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1.1.1 Addition on a Turing machine |
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11 | (2) |
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1.1.2 The Church-Turing thesis |
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13 | (1) |
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1.1.3 The universal Turing machine |
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14 | (1) |
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1.1.4 The probabilistic Turing machine |
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15 | (1) |
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1.1.5 * The halting problem |
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15 | (1) |
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1.2 The circuit model of computation |
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16 | (6) |
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17 | (1) |
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1.2.2 Elementary logic gates |
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18 | (3) |
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1.2.3 Universal classical computation |
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21 | (1) |
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1.3 Computational complexity |
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22 | (12) |
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1.3.1 Tractable vs. intractable problems |
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23 | (7) |
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30 | (4) |
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1.3.3 * The Chernoff bound |
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34 | (1) |
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1.4 * Computing dynamical systems |
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34 | (5) |
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1.4.1 * Deterministic chaos |
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35 | (2) |
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1.4.2 * Algorithmic complexity |
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37 | (2) |
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1.5 Energy and information |
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39 | (4) |
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39 | (1) |
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1.5.2 Landauer's principle |
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40 | (2) |
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1.5.3 Extracting work from information |
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42 | (1) |
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1.6 Reversible computation |
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43 | (5) |
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1.6.1 Toffoli and Fredkin gates |
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45 | (1) |
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1.6.2 * The billiard-ball computer |
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46 | (2) |
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1.7 * Energy dissipation in computation |
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48 | (6) |
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1.7.1 * Experimental realization of a Maxwell's demon |
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48 | (1) |
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1.7.2 * Experimental verification of Landauer's principle |
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49 | (1) |
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1.7.3 * Energy dissipation in real classical computer |
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50 | (1) |
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1.7.4 * Experimental realization of reversible computers |
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51 | (2) |
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1.7.5 * Neuromorfic computing |
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53 | (1) |
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1.8 A guide to the bibliography |
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54 | (1) |
2 Introduction to quantum mechanics |
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55 | (42) |
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2.1 The Stern-Gerlach experiment |
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56 | (3) |
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2.2 Young's double-slit experiment |
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59 | (4) |
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2.3 The postulates of quantum mechanics |
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63 | (9) |
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2.3.1 Dynamical evolution |
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63 | (1) |
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2.3.2 Outcomes of a measurement |
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64 | (3) |
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2.3.3 The post-measurement state |
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67 | (2) |
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2.3.4 Heisenberg's uncertainty principle |
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69 | (3) |
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72 | (5) |
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77 | (4) |
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81 | (8) |
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86 | (3) |
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2.7 The Schmidt decomposition |
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89 | (2) |
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91 | (2) |
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2.9 Generalized measurements |
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93 | (3) |
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94 | (2) |
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2.10 A guide to the bibliography |
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96 | (1) |
3 Quantum computation |
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97 | (60) |
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98 | (5) |
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3.1.1 Pure qubit states: The Bloch sphere |
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99 | (1) |
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3.1.2 Mixed qubit states: The Bloch ball |
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100 | (3) |
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3.2 Measuring the state of a qubit |
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103 | (2) |
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103 | (1) |
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104 | (1) |
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3.3 The circuit model of quantum computation |
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105 | (3) |
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108 | (3) |
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3.4.1 Rotations of the Bloch sphere |
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109 | (2) |
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3.5 Controlled gates and entanglement generation |
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111 | (5) |
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115 | (1) |
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3.6 Hamiltonian model for one-and two-qubit gates |
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116 | (1) |
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3.7 Universal quantum gates |
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117 | (10) |
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3.7.1 * Preparation of the initial state |
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124 | (3) |
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127 | (1) |
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128 | (4) |
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132 | (2) |
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134 | (7) |
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3.11.1 Adiabatic condition |
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136 | (1) |
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137 | (4) |
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3.12 * Non-Abelian geometric phase |
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141 | (4) |
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3.13 Adiabatic quantum computation |
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145 | (4) |
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3.14 * Maximum speed of quantum gates |
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149 | (3) |
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3.14.1 * Speed limit of an autonomous time evolution |
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150 | (1) |
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3.14.2 * Speed limit of single-qubit gates |
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151 | (1) |
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3.15 * Holonomic quantum computation |
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152 | (3) |
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3.16 A guide to the bibliography |
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155 | (2) |
4 Quantum algorithms |
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157 | (38) |
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157 | (4) |
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4.1.1 The Deutsch-Jozsa problem |
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158 | (1) |
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4.1.2 * An extension of Deutsch's algorithm |
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159 | (2) |
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161 | (7) |
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4.2.1 Searching one item out of four |
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161 | (2) |
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4.2.2 Searching one item out of N |
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163 | (1) |
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4.2.3 Geometric visualization |
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164 | (2) |
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4.2.4 Searching by adiabatic quantum evolution |
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166 | (2) |
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4.3 The quantum Fourier transform |
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168 | (3) |
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4.4 Quantum phase estimation |
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171 | (2) |
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4.5 * Finding eigenvalues and eigenvectors |
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173 | (2) |
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4.6 Period finding and Shor's algorithm |
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175 | (4) |
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4.7 Quantum computation of dynamical systems |
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179 | (11) |
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4.7.1 Quantum simulation of the Schrodinger equation |
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179 | (4) |
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4.7.2 * The quantum baker's map |
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183 | (2) |
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4.7.3 * The quantum sawtooth map |
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185 | (3) |
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4.7.4 Information extraction for dynamical quantum systems |
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188 | (2) |
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4.8 Universal quantum simulation |
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190 | (2) |
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4.9 A guide to the bibliography |
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192 | (3) |
5 Quantum communication |
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195 | (46) |
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5.1 Classical cryptography |
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195 | (4) |
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196 | (1) |
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5.1.2 The public-key cryptosystem |
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197 | (1) |
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198 | (1) |
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5.2 The no-cloning theorem |
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199 | (8) |
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5.2.1 Faster-than-light transmission of information? |
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201 | (2) |
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5.2.2 * The no-signalling condition |
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203 | (1) |
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5.2.3 * Universal quantum cloning |
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204 | (2) |
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5.2.4 * The universal-NOT gate |
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206 | (1) |
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207 | (5) |
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207 | (3) |
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210 | (2) |
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212 | (3) |
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5.5 Quantum teleportation |
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215 | (5) |
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5.5.1 * Conclusive teleportation |
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219 | (1) |
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5.6 Quantum mechanics with continuous variables |
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220 | (17) |
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5.6.1 * General framework for Gaussian states |
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233 | (4) |
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5.7 Quantum cryptography with continuous variables |
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237 | (3) |
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5.8 A guide to the bibliography |
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240 | (1) |
6 Entanglement and non-classical correlations |
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241 | (46) |
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6.1 Definition of entanglement |
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241 | (2) |
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242 | (1) |
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6.2 Bipartite separability criteria |
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243 | (5) |
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6.2.1 The Peres separability criterion |
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244 | (1) |
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245 | (1) |
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6.2.3 Entanglement witnesses |
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246 | (2) |
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6.2.4 Positive maps and witnesses |
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248 | (1) |
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248 | (4) |
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250 | (2) |
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6.4 The von Neumann entropy |
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252 | (4) |
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6.4.1 Example 1: source of orthogonal pure states |
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255 | (1) |
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6.4.2 Example 2: source of non-orthogonal pure states |
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255 | (1) |
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6.5 Entanglement concentration |
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256 | (7) |
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6.5.1 * Entanglement of a random state |
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260 | (3) |
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6.6 Requirements for bipartite entanglement measures |
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263 | (1) |
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6.7 Other entanglement measures |
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264 | (2) |
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264 | (1) |
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265 | (1) |
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6.8 * Multipartite entanglement |
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266 | (3) |
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6.8.1 * Monogamy of entanglement and tangle measures |
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268 | (1) |
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269 | (8) |
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270 | (3) |
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273 | (1) |
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274 | (1) |
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6.9.4 * Other measures of quantum correlations |
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275 | (2) |
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6.10 * Quantum discord in continuous systems |
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277 | (2) |
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6.10.1 * Entropy of a Gaussian state |
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277 | (1) |
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6.10.2 * Discord of a Gaussian state |
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278 | (1) |
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6.11 * Entropies in physics |
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279 | (6) |
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6.11.1 * Thermodynamic entropy |
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280 | (2) |
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6.11.2 * Statistical entropy |
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282 | (2) |
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6.11.3 * Dynamical Kolmogorov-Sinai entropy |
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284 | (1) |
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6.12 A guide to the bibliography |
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285 | (2) |
7 Decoherence |
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287 | (58) |
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7.1 The Kraus representation |
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287 | (6) |
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7.2 Decoherence models for a single qubit |
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293 | (14) |
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7.2.1 The quantum black box |
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294 | (1) |
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7.2.2 Measuring a quantum operation acting on a qubit |
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295 | (1) |
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7.2.3 Quantum circuits simulating noise channels |
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296 | (2) |
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7.2.4 The bit-flip channel |
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298 | (1) |
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7.2.5 The phase-flip channel |
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299 | (1) |
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7.2.6 The bit-phase-flip channel |
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300 | (1) |
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7.2.7 The depolarizing channel |
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301 | (1) |
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302 | (1) |
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303 | (2) |
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305 | (2) |
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7.3 * The Bloch-Fano representation |
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307 | (3) |
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7.3.1 * Bloch-Fano representation of a state |
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307 | (1) |
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7.3.2 * Bloch-Fano representation of a quantum operation |
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308 | (2) |
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310 | (14) |
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7.4.1 * Derivation of the master equation |
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311 | (8) |
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7.4.2 The master equation and quantum operations |
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319 | (3) |
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7.4.3 The master equation for a single qubit |
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322 | (2) |
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7.5 * Non-Markovian quantum dynamics |
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324 | (5) |
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7.6 Quantum to classical transition |
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329 | (6) |
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329 | (1) |
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7.6.2 Decoherence and destruction of cat states |
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330 | (5) |
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7.7 Decoherence and quantum measurements |
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335 | (9) |
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7.7.1 * Weak measurements |
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337 | (3) |
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7.7.2 * Decoherence and quantum trajectories |
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340 | (4) |
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7.8 A guide to the bibliography |
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344 | (1) |
8 Quantum information theory |
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345 | (34) |
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8.1 Classical data compression |
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346 | (5) |
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8.1.1 Shannon's noiseless coding theorem |
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346 | (2) |
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8.1.2 Examples of data compression |
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348 | (1) |
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8.1.3 Capacity of classical channels |
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349 | (2) |
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8.2 Quantum data compression |
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351 | (6) |
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8.2.1 Schumacher's quantum noiseless coding theorem |
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351 | (1) |
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8.2.2 Compression of an n-qubit message |
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352 | (2) |
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8.2.3 Example 1: two-qubit messages |
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354 | (1) |
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8.2.4 Example 2: three-qubit messages |
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355 | (2) |
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8.3 Accessible information |
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357 | (6) |
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358 | (1) |
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8.3.2 Example 1: two non-orthogonal pure states |
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359 | (3) |
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8.3.3 * Example 2: three non-orthogonal pure states |
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362 | (1) |
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8.4 Capacities of quantum channels |
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363 | (8) |
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364 | (1) |
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365 | (6) |
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8.5 * Quantum memory channels |
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371 | (7) |
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8.6 A guide to the bibliography |
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378 | (1) |
9 Quantum error correction |
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379 | (38) |
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9.1 The three-qubit bit-flip code |
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381 | (3) |
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9.2 The three-qubit phase-flip code |
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384 | (1) |
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9.3 The nine-qubit Shor code |
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385 | (4) |
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9.4 General properties of quantum error correction |
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389 | (3) |
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9.4.1 The quantum Hamming bound |
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391 | (1) |
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392 | (4) |
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9.5.1 The nine-qubit Shor code revisited |
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392 | (2) |
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9.5.2 * General formalism for stabilizer codes |
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394 | (1) |
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9.5.3 * Logical operators for stabilizer codes |
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395 | (1) |
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9.6 * The five-qubit code |
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396 | (3) |
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9.7 Decoherence-free subspaces |
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399 | (5) |
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9.7.1 * Conditions for decoherence-free dynamics |
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401 | (1) |
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9.7.2 * The spin-boson model |
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402 | (2) |
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9.8 * Dynamical decoupling |
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404 | (3) |
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9.8.1 * Explicit form of control Hamiltonian |
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406 | (1) |
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407 | (4) |
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9.10 Fault-tolerant quantum computation |
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411 | (4) |
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9.10.1 Avoidance of error propagation |
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411 | (2) |
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9.10.2 Fault-tolerant quantum gates |
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413 | (1) |
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9.10.3 The noise threshold for quantum computation |
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414 | (1) |
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9.11 A guide to the bibliography |
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415 | (2) |
10 Principles of experimental implementations of quantum protocols |
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417 | (40) |
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10.1 Cavity quantum electrodynamics |
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418 | (6) |
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10.1.1 Interaction of a two-level atom with a classical field |
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420 | (1) |
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10.1.2 The Jaynes-Cummings model |
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421 | (1) |
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422 | (1) |
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10.1.4 Entanglement generation |
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423 | (1) |
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10.2 The ion-trap quantum computer |
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424 | (9) |
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425 | (2) |
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427 | (6) |
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433 | (10) |
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10.3.1 Spins in semiconductors |
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433 | (1) |
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434 | (3) |
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10.3.3 Superconducting qubit circuits |
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437 | (6) |
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10.4 Quantum communication with photons |
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443 | (11) |
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444 | (2) |
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10.4.2 Non-linear optics and probabilistic gates |
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446 | (3) |
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10.4.3 Experimental quantum-key distribution |
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449 | (5) |
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10.5 Problems and prospects |
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454 | (1) |
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10.6 A guide to the bibliography |
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455 | (2) |
11 Quantum information in many-body systems |
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457 | (78) |
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458 | (8) |
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458 | (3) |
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11.1.2 Arrays of coupled QED cavities |
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461 | (5) |
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11.2 Emergence of quantum correlations |
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466 | (3) |
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467 | (2) |
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11.3 The spin-1/2 quantum Ising chain |
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469 | (15) |
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11.3.1 Jordan-Wigner transformation |
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470 | (2) |
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11.3.2 Diagonalization of the Ising chain |
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472 | (6) |
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11.3.3 Two-spin concurrence |
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478 | (1) |
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11.3.4 Entanglement block entropy |
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479 | (2) |
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11.3.5 The Ising model revisited: Kitaev chain |
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481 | (3) |
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11.4 Area-law scaling of the entanglement |
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484 | (3) |
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11.5 Matrix product states |
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487 | (5) |
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11.5.1 Examples of MPS wave functions |
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490 | (2) |
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11.6 Graphical representation of matrix product states |
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492 | (11) |
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11.6.1 Expectation values of observables |
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494 | (2) |
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11.6.2 * Scaling of correlation functions with the distance |
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496 | (2) |
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498 | (2) |
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11.6.4 Schmidt decomposition of a MPS |
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500 | (3) |
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11.7 Ground-state search in the Hilbert space corner |
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503 | (9) |
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11.7.1 Density-matrix renormalization group |
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506 | (4) |
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11.7.2 * DMRG as a variational optimization over the MPS class |
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510 | (2) |
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11.8 Time evolution of matrix product states |
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512 | (7) |
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11.8.1 Finite-temperature calculations |
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515 | (2) |
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11.8.2 Mixed-state time evolution |
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517 | (2) |
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11.9 * General tensor-network structures |
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519 | (10) |
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11.9.1 * Projected entangled pair states |
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519 | (5) |
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11.9.2 * Hierarchical tensor networks |
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524 | (5) |
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11.10 A guide to the bibliography 526 Conclusions and prospects |
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529 | (6) |
Appendix A: Elements of linear algebra |
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535 | (30) |
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A.1 Finite-dimensional vector spaces |
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535 | (22) |
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A.1.1 Basic properties of vector spaces |
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535 | (1) |
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A.1.2 Inner product and norm of a vector |
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536 | (2) |
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A.1.3 Linear independence and the notion of basis |
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538 | (2) |
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540 | (5) |
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545 | (2) |
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A.1.6 Matrix decompositions |
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547 | (8) |
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A.1.7 Symplectic decompositions |
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555 | (2) |
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A.2 Infinite-dimensional vector spaces |
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557 | (8) |
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A.2.1 Discrete and continuous bases |
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557 | (1) |
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A.2.2 The Dirac delta function |
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558 | (1) |
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A.2.3 Orthonormality and completeness relations |
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559 | (1) |
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A.2.4 Position and momentum representations |
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560 | (3) |
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A.2.5 Position and momentum operators |
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563 | (2) |
Appendix B: Solutions to the exercises |
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565 | (86) |
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565 | (1) |
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566 | (7) |
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573 | (11) |
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584 | (1) |
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585 | (9) |
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594 | (6) |
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600 | (15) |
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615 | (3) |
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618 | (7) |
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625 | (19) |
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644 | (4) |
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648 | (3) |
Bibliography |
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651 | (26) |
Index |
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677 | |