# Progressive field-state collapse and quantum non-demolition photon counting

@article{Guerlin2007ProgressiveFC, title={Progressive field-state collapse and quantum non-demolition photon counting}, author={Christine Guerlin and Julien Bernu and Samuel Deleglise and Cl{\'e}ment Sayrin and S. Gleyzes and Stefan Kuhr and M. Brune and Jean-Michel Raimond and Serge Haroche}, journal={Nature}, year={2007}, volume={448}, pages={889-893} }

The irreversible evolution of a microscopic system under measurement is a central feature of quantum theory. From an initial state generally exhibiting quantum uncertainty in the measured observable, the system is projected into a state in which this observable becomes precisely known. Its value is random, with a probability determined by the initial system’s state. The evolution induced by measurement (known as ‘state collapse’) can be progressive, accumulating the effects of elementary state…

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