- #1
MichPod
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Why protective measurement is important to understand whether the wave function is the ontic property of a single particle and not of the ensabmle of similarly prepared particles?
I need some help with understanding the following topic (which is currently above my level so I may easily miss some simple important points).
There are some recent articles (Why protective measurement establishes the reality of the wave functionShan Gao, 2018) which claim that being able to measure average values of many observables for a single particle in protective measurement (and by that calculating the wave function) somehow proves that the wave function is the property of a single particle (and not of the ensamble of particles).
In my view, when we somehow "protect" the measurement, i.e. maintain the wave function of the particle non-changed, and produce a set of measurements, we actually are doing something which may be equivalent to producing a set of measurements on the ensamble of different particles. For what I see, to ensure a protective measurement, we need to know some characteristics of the wave function ahead to "protect" it with Zeno effect or otherwise. We cannot just take an arbitrary particle with not known wave function and proceed with protective measurements of it. So it may be said that a protective measurement "imposes" the original wave function firstly by already knowing quite much of what it may be. So I fail to see much difference (theoretical one) between conducting a set of protected measurements of a single particle vs a set of regular measurements on a pure ensamble of particles which have a same wave function.
I have no doubt that realizing a set of protective measurements on a single particle may be a serious experimental challenge, but I fail to see how being able to do them proves anyting new on the nature of the wave function.
I need some help with understanding the following topic (which is currently above my level so I may easily miss some simple important points).
There are some recent articles (Why protective measurement establishes the reality of the wave functionShan Gao, 2018) which claim that being able to measure average values of many observables for a single particle in protective measurement (and by that calculating the wave function) somehow proves that the wave function is the property of a single particle (and not of the ensamble of particles).
In my view, when we somehow "protect" the measurement, i.e. maintain the wave function of the particle non-changed, and produce a set of measurements, we actually are doing something which may be equivalent to producing a set of measurements on the ensamble of different particles. For what I see, to ensure a protective measurement, we need to know some characteristics of the wave function ahead to "protect" it with Zeno effect or otherwise. We cannot just take an arbitrary particle with not known wave function and proceed with protective measurements of it. So it may be said that a protective measurement "imposes" the original wave function firstly by already knowing quite much of what it may be. So I fail to see much difference (theoretical one) between conducting a set of protected measurements of a single particle vs a set of regular measurements on a pure ensamble of particles which have a same wave function.
I have no doubt that realizing a set of protective measurements on a single particle may be a serious experimental challenge, but I fail to see how being able to do them proves anyting new on the nature of the wave function.
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