Editing Quantum Zeno effect (section)

==Various realizations and general definition==
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The treatment of the Zeno effect as a [[paradox]] is not limited to the processes of [[quantum decay]]. In general, the term ''Zeno effect'' is applied to various transitions, and sometimes these transitions may be very different from a mere "decay" (whether exponential or non-exponential).

One realization refers to the observation of an object ([[Zeno's arrow]], or any [[quantum particle]]) as it leaves some region of space. In the 20th century, the trapping (confinement) of a particle in some region by its observation outside the region was considered as nonsensical, indicating some non-completeness of quantum mechanics.<ref name="miel94">
{{cite journal
 |last1=Mielnik |first1=B.
 |year=1994
 |title=The screen problem
 |journal=[[Foundations of Physics]]
 |volume=24|issue=8|pages=1113–1129
 |bibcode=1994FoPh...24.1113M
 |doi=10.1007/BF02057859
|s2cid=121708226
 }}</ref> Even as late as 2001, confinement by absorption was considered as a paradox.<ref name="yama01">
{{cite journal
 |last1=Yamane |first1=K.
 |last2=Ito |first2=M.
 |last3=Kitano |first3=M.
 |year=2001
 |title=Quantum Zeno effect in optical fibers
 |journal=[[Optics Communications]]
 |volume=192 |issue=3–6 |pages=299–307
 |bibcode=2001OptCo.192..299Y
 |doi=10.1016/S0030-4018(01)01192-0
}}</ref> Later, similar effects of the suppression of [[Raman scattering]] was considered an expected ''effect'',<ref name="thun">
{{cite journal
 |last1=Thun |first1=K.
 |last2=Peřina |first2=J.
 |last3=Křepelka |first3=J.
 |year=2002
 |title=Quantum Zeno effect in Raman scattering
 |journal=[[Physics Letters A]]
 |volume=299 |issue=1 |pages=19–30
 |bibcode=2002PhLA..299...19T
 |doi=10.1016/S0375-9601(02)00629-1
}}</ref><ref>
{{cite journal
 |last1=Peřina |first1=J.
 |year=2004
 |title=Quantum Zeno effect in cascaded parametric down-conversion with losses
 |journal=[[Physics Letters A]]
 |volume=325|issue=1|pages=16–20
 |bibcode=2004PhLA..325...16P
 |doi=10.1016/j.physleta.2004.03.026
}}</ref><ref name="kouz05">
{{cite journal
 |last1=Kouznetsov |first1=D.
 |last2=Oberst |first2=H.
 |year=2005
 |title=Reflection of Waves from a Ridged Surface and the Zeno Effect
 |journal=[[Optical Review]]
 |volume=12 |issue=5 |pages=1605–1623
 |bibcode=2005OptRv..12..363K
 |doi=10.1007/s10043-005-0363-9
|s2cid=55565166
 }}</ref> not a paradox at all. The absorption of a photon at some wavelength, the release of a photon (for example one that has escaped from some mode of a fiber), or even the relaxation of a particle as it enters some region, are all processes that can be interpreted as measurement. Such a measurement suppresses the transition, and is called the Zeno effect in the scientific literature.

In order to cover all of these phenomena (including the original effect of suppression of quantum decay), the Zeno effect can be defined as a class of phenomena in which some transition is suppressed by an interaction – one that allows the interpretation of the resulting state in the terms 'transition did not yet happen' and 'transition has already occurred', or 'The proposition that the evolution of a quantum system is halted' if the state of the system is continuously measured by a macroscopic device to check whether the system is still in its initial state.<ref name="pano01">
{{cite journal
 |last1=Panov |first1=A. D.
 |year=2001
 |title=Quantum Zeno effect in spontaneous decay with distant detector
 |journal=[[Physics Letters A]]
 |volume=281 |issue=1|page=9
 |arxiv=quant-ph/0101031
 |bibcode=2001PhLA..281....9P
 |doi=10.1016/S0375-9601(01)00094-9
|s2cid=18357530
 }}</ref>