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Quantum Projection Noise: Population Fluctuations in 2-Level Systems



Wayne M. Itano, James C. Bergquist, John J. Bollinger, J M. Gilligan, D J. Heinzen, F L. Moore, M G. Raizen, David J. Wineland


Measurements of internal energy states of atomic ions confined in traps can be used to illustrate fundamental properties of quantum systems, because long relaxation times and observation times are available. In the experiments described here, a single ion or a few identical ions were prepared in well-defined superpositions of two internal energy eigenstates. The populations of the energy levels were then measured. For an individual ion, the outcome of the measurement is uncertain, unless the amplitude for one of the two eigenstates is zero, and is completely uncertain when the magnitudes of the two amplitudes are equal.
Physical Review A (Atomic, Molecular and Optical Physics)


Itano, W. , Bergquist, J. , Bollinger, J. , Gilligan, J. , Heinzen, D. , Moore, F. , Raizen, M. and Wineland, D. (1993), Quantum Projection Noise: Population Fluctuations in 2-Level Systems, Physical Review A (Atomic, Molecular and Optical Physics), [online], (Accessed July 22, 2024)


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Created January 1, 1993, Updated February 17, 2017