The quantum challenge : modern research on the foundations of quantum mechanics / George Greenstein, Arthur G. Zajonc.

Format:

Book

Author/Creator:

Greenstein, George, 1940-

Contributor:

Zajonc, Arthur

Series:

Jones and Bartlett series in physics and astronomy

Jones and Bartlett titles in physics and astronomy

Language:

English

Subjects (All):

Quantum theory--Research.

Quantum theory.

Research.

Physical Description:

xviii, 300 pages : illustrations ; 24 cm.

Edition:

Second edition.

Place of Publication:

Sudbury, Mass. : Jones and Bartlett Publishers, [2006]

Summary:

The Quantum Challenge, Second Edition is an engaging and thorough treatment of the extraordinary phenomena of quantum mechanics, and of the enormous challenge they present to our conception of the physical world. Traditionally, the thrill of grappling with such issues is reserved for practicing scientists, while physical science, mathematics, and engineering students are often isolated from these inspiring questions. This book was written to remove this isolation.

George Greenstein and Arthur G. Zajonc present the puzzles of quantum mechanics using vivid references to contemporary experiments. The authors focus on the most striking and conceptually significant quantum phenomena, together with a clear theoretical treatment of each. The depth and extent of the challenge of quantum mechanics become increasingly compelling as they move from the simplest experiments involving single photons or particles, to the famous Einstein-Podolsky-Rosen effect and Bell's Theorem, and then to macroscopic quantum phenomena.

Contents:

1 Matter Waves 1

1.1 An Experiment 1

1.2 A Second Experiment 5

1.3 Locality 7

1.4 Beyond the Electron 8

Neutrons 8

Atoms 9

Bose-Einstein Condensates 9

The Experiment 12

1.5 Quantum Theory of Two-Slit Interference 13

1.6 Critique of the Quantum-Mechanical Account 18

2 Photons 23

2.1 Do Photons Exist? 24

Detection and the Quantum of Light 24

Photoelectric Effect 24

Anticoincidences 28

The Hanbury-Brown and Twiss Experiment 30

Photons at Last 34

Remarks 36

2.2 Wave-Particle Duality for Single Photons 37

The Mystery of Wave-Particle Duality 38

Delayed Choice 39

3 The Uncertainty Principle 45

3.1 The Pfleegor-Mandel Experiment 45

Two Lasers, One Photon 45

The Heisenberg Uncertainty Principle 47

Uncertainty in the Pfleegor-Mandel Experiment 50

3.2 Reflections on the Uncertainty Principle 52

Quantum Uncertainty versus Classical Ignorance 52

Interpretation of the Uncertainty Principle 53

The Uncertainty Principle and Causality 53

The Uncertainty Principle and Descriptions of Natural Phenomena 55

3.3 Some Consequences of the Uncertainty Principle 56

Atoms 57

Nuclei 58

Trajectories 58

3.4 The Energy-Time Uncertainty Relation 59

Average Properties of Systems 59

Lifetimes and Line Widths 61

Time and Frequency Standards 62

More on Causality: The Uncertainty Principle and an Ambiguity in Time 63

Origin of the Energy-Time Uncertainty Relation 67

3.5 Squeezed Light and the Detection of Gravitational Radiation 72

Gravitational Radiation 72

Squeezed States of the Simple Harmonic Oscillator 73

Squeezed States of Light 79

3.6 Quantum Non-Demolition Measurements 83

Back Action and the Detection of Gravitational Radiation 83

Seeing a Single Photon Without Destroying It 86

4 Complementarity 91

4.1 Bohr's Discovery of Complementarity 92

Como, 1927 94

4.2 Einstein's Attack on Complementarity 95

The Solvay Meetings: Complementarity between Which-Path Information and Interference 96

Complementarity in the Energy-Time Uncertainty Relation 99

4.3 The New Paradigm: Information 102

Quantum Beats 102

Theory of Quantum Beats: Complementarity 105

Orthogonality and the Role of Information in Quantum Beats 108

Partial Information 110

4.4 Is Complementarity Enforced by the Uncertainty Principle? 113

An Experiment 113

The Aharonov-Bohm Effect 117

Momentum Kicks in Interference Experiments 120

Quantum Momentum Transfer 120

5 The EPR Paradox and Bell's Theorem 123

5.1 The EPR Argument 125

The Argument 127

Locality 130

Reality and Hidden Variables 130

5.2 The BKS Theorem and Contextuality 133

Sketch of the BKS Proof 133

5.3 Hidden-Variable Theories 135

Elementary Example of a Hidden-Variable Theory 137

5.4 Bell's Theorem 139

Proof of Bell's Theorem 140

Mermin's "Local Reality Machine" 142

6 Testing Bell's Inequalities: Entangled States 149

6.1 Tests of Bell's Inequalities 150

Early Work 150

Two-Photon Entangled States 151

Linear Polarization 153

The Aspect Experiments 157

6.2 Bohm's Nonlocal Hidden-Variable Theory 162

6.3 The Mystery of the EPR Correlations 166

6.4 Does Quantum Nonlocality Violate the Principle of Relativity? 167

6.5 Quantum Nonlocality: A New Source and a New Experiment 169

6.6 The Greenberger-Horne-Zeilinger Theorem 173

Quantum-Mechanical Analysis 174

Local Realism Analysis 176

Experimental Test 177

6.7 Comments on Quantum Nonlocality 183

7 Schrodinger's Cat 185

7.1 What Is the Cat Paradox? 186

7.2 Superpositions and Mixtures: A More Technical Statement of the Cat Paradox 187

7.3 Further Discussion of the Difference Between Superpositions and Mixtures: Spin 188

7.4 Why Is Quantum Behavior Not Observed in the Large-Scale World? 189

Interference 190

Uncertainty Principle 190

Quantum Tunneling 190

7.5 Decoherence 193

7.6 Watching Decoherence 199

7.7 Laboratory Realizations of Macroscopic Quantum Behavior 202

Conditions for the Existence of Macroscopic Quantum Behavior 203

Macroscopic Quantum Tunneling: SQUIDS 205

Macroscopic Quantum Coherence 207

A Microscopic Analog 209

8 Measurement 215

8.1 The Measurement Problem 215

The Collapse of the Wave Function 215

Is the Collapse of the Wave Function Described by the Schrodinger Equation? 219

Quantum Theory of Measurement: The Infinite Regress 222

Termination of the Infinite Regress: The Projection Postulate 224

8.2 The Active Nature of Measurement in Quantum Mechanics 227

Mixtures and Superpositions 227

What Is the State of the Photon a Decaying Atom Emits? 229

The Quantum Zeno Effect 231

8.3 Attempts to Solve the Measurement Problem 237

Small Detectors and Big Detectors: Decoherence 237

Does Decoherence Solve the Measurement Problem? 239

Decoherence Can Be Undone 239

Coherence Can Be Moved Around: The Quantum Eraser 240

9 Quantum Information and Computation 245

9.1 Bits and Qubits 246

9.2 Quantum Cryptography 247

Quantum Key Distribution Via Single-Particle Superposition 248

Quantum Key Distribution Via Entanglement 251

9.3 Quantum Teleportation 252

Quantum Information Cannot Be Read 253

Quantum Teleportation 254

Experimental Realization of Quantum Teleportation 257

9.4 Quantum Computation: The Deutsch-Jozsa Algorithm 259

An Analogy 260

The Deutsch-Jozsa Problem 262

Logical Operations on Quantum Registers 262

The Deutsch-Jozsa Algorithm 264

Logical Operations and U[subscript f] 267

A Toy Quantum Computer 268

A Real Quantum Computer 271

9.5 Comments on Quantum Machines 277

Appendix A Bibliography of Experiments for the Undergraduate Laboratory 281

Chapter 1: Matter Waves 281

Chapter 2: Photons 282

Chapter 3: The Uncertainty Principle 282

Chapter 4: Complementarity 283

Chapter 6: Testing Bell's Inequalities: Entangled States 283

Chapter 8: Measurement 284.

Notes:

Includes bibliographical references (pages 285-292) and index.

ISBN:

076372470X

OCLC:

59002779