Abstract
We discuss the question of linear momentum conservation when an atom coupled to a laser field enters into a state which is not an eigenstate of the linear momentum. Such a situation happens in the recently demonstrated laser cooling of atoms by velocity selective coherent population trapping. We show that this process can be understood as a filtering of the atomic state by the laser field taken as a classical measuring apparatus. In a different approach, the laser field can be taken as a quantized system; then the filtering process leads to an “entangled state” of the atom and the field.
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References
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Aspect, A., Kaiser, R. Linear momentum conservation in coherent population trapping: A case study for a quantum filtering process. Found Phys 20, 1413–1428 (1990). https://doi.org/10.1007/BF01883515
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DOI: https://doi.org/10.1007/BF01883515