#### Cthugha

Science Advisor

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Well, you might want to become a politician. I have rarely seen a quote taken so out of context. ;)Exactly, we just have to read the first paragraph of the introduction of the above cited PRA paper to set the records straight:

[...]

Indeed, for a textbook treatment of "quantum jumps" (neglecting however spontaneous emission) see the famous Wigner-Weisskopf treatment of decays, nicely covered in

O. Nachtman, Elementary Particle Physics, Springer

The relevant part is of course:

Of course you do not need quantum jumps (apart from the meaning that the energies of the states taken on are of course discrete) to describe basic introductory textbook physics, but also of course Wigner-Weisskopf is of absolutely no use beyond weak coupling. And strong coupling /dressed states are the topic of the cited paper and also of the major part of quantum optics within the last 30 years or so. As soon as you need to take the environment seriously, you need a more sophisticated description. And the number of real working physicists working on still reproducing basic textbook physics is somewhat small...Wiseman said:However, it was the electron shelving experiments of Itano and co-workers [10] which refocused attention on the conditional dynamics of individual atoms. Subsequent work on waiting time distributions [11,12] led to a renewal of interest in quantum jump descriptions [13]. It was shown by Carmichael [14] that quantum jumps are an implicit part of standard photodetection theory. This link between continuous quantum measurement theory and stochastic quantum evolution for the pure state of the system was considered by many other workers around the same time and subsequently [15–24]. Independently, Dalibard, Castin, and Mölmer [25] derived the same stochastic Schro¨dinger equations, driven by the need for efficient methods for numerically simulating moderately large quantum systems. This technique, called Monte Carlo wave-function simulations, has been applied to great advantage in describing the optical cooling of a fluorescent atom [26–30]. Regardless of the motivation for their use, the evolution of systems undergoing quantum jumps and other stochastic quantum processes is known widely as quantum trajectories [14].