Book contents
- Frontmatter
- Contents
- Acknowledgements
- 1 Introduction
- 2 Field quantization
- 3 Coherent states
- 4 Emission and absorption of radiation by atoms
- 5 Quantum coherence functions
- 6 Beam splitters and interferometers
- 7 Nonclassical light
- 8 Dissipative interactions and decoherence
- 9 Optical test of quantum mechanics
- 10 Experiments in cavity QED and with trapped ions
- 11 Applications of entanglement: Heisenberg-limited interferometry and quantum information processing
- Appendix A The density operator, entangled states, the Schmidt decomposition, and the von Neumann entropy
- Appendix B Quantum measurement theory in a (very small) nutshell
- Appendix C Derivation of the effective Hamiltonian for dispersive (far off-resonant) interactions
- Appendix D Nonlinear optics and spontaneous parametric down-conversion
- Index
- References
9 - Optical test of quantum mechanics
Published online by Cambridge University Press: 05 September 2012
- Frontmatter
- Contents
- Acknowledgements
- 1 Introduction
- 2 Field quantization
- 3 Coherent states
- 4 Emission and absorption of radiation by atoms
- 5 Quantum coherence functions
- 6 Beam splitters and interferometers
- 7 Nonclassical light
- 8 Dissipative interactions and decoherence
- 9 Optical test of quantum mechanics
- 10 Experiments in cavity QED and with trapped ions
- 11 Applications of entanglement: Heisenberg-limited interferometry and quantum information processing
- Appendix A The density operator, entangled states, the Schmidt decomposition, and the von Neumann entropy
- Appendix B Quantum measurement theory in a (very small) nutshell
- Appendix C Derivation of the effective Hamiltonian for dispersive (far off-resonant) interactions
- Appendix D Nonlinear optics and spontaneous parametric down-conversion
- Index
- References
Summary
Over the past three decades or so, experiments of the type called Gedanken have become real. Recall the Schrödinger quote from Chapter 8: “… we never experiment with just one electron or atom or (small) molecule.” This is no longer true. We can do experiments involving single atoms or molecules and even on single photons, and thus it becomes possible to demonstrate that the “ridiculous consequences” alluded to by Schrödinger are, in fact, quite real. We have already discussed some examples of single-photon experiments in Chapter 6, and in Chapter 10 we shall discuss experiments performed with single atoms and single trapped ions. In the present chapter, we shall elaborate further on experimental tests of fundamentals of quantum mechanics involving a small number of photons. By fundamental tests we mean tests of quantum mechanics against the predictions of local realistic theories (i.e. hidden variable theories). Specifically, we discuss optical experiments demonstrating violations of Bell's inequalities, violations originally discussed by Bell in the context of two spin-one-half particles. Such violations, if observed experimentally, falsify local realistic hidden-variable theories. Locality refers to the notion, familiar in classical physics, that there cannot be a causal relationship between events with space-like separations. That is, the events cannot be connected by any signal moving at, or less than, the speed of light; i.e. the events are outside the light-cone. But in quantum mechanics, it appears that nonlocal effects, effects seemly violating the classical notion of locality in a certain restricted sense, are possible.
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- Information
- Introductory Quantum Optics , pp. 213 - 237Publisher: Cambridge University PressPrint publication year: 2004