We study the quantum-mechanical uncertainty relation originating from the successive measurement of two observables
A^ and
B^, with eigenvalues
an and
bm, respectively, performed on the same system. We use an extension of the von Neumann model of measurement, in which two probes interact with the same system proper at two successive times, so we can exhibit how the disturbing effect of the first interaction affects the second measurement. Detecting the statistical properties of the second {\em probe} variable
Q2 conditioned on the first {\em probe} measurement yielding
Q1 we obtain information on the statistical distribution of the {\em system} variable
bm conditioned on having found the system variable
an in the interval
δa around
a(n). The width of this statistical distribution as function of
δa constitutes an {\em uncertainty relation}. We find a general connection of this uncertainty relation with the commutator of the two observables that have been measured successively. We illustrate this relation for the successive measurement of position and momentum in the discrete and in the continuous cases and, within a model, for the successive measurement of a more general class of observables.
In quantum mechanics, the uncertainty is fundamental concept, so its underlying meaning has been argued intensively due to its weird properties. On this account, there has been various fomulations expressing the uncertainty principle in dierent ways. In this paper, the new entropic uncertainty relations will be suggested showing dierent aspects of uncertainty as we consider successive measurements. Already, Deutsch and Unk suggested entropic uncertainty relations, so our work will be to modify it as focusing on another aspect (error-disurbance) of uncertainry. The uncertainty relations Heisenberg is the rst man who suggested the uncertainty principle. In 1927 [1], he proposed the uncertainty relation,
Uncertainties in successive measurements of general canonically conjugate variables are examined. Such operators are approached within a limiting procedure of the Pegg–Barnett type. Dealing with unbounded observables, we should take into account a finiteness of detector resolution. An appropriate reformulation of two scenarios of successive measurements is proposed and motivated. Uncertainties are characterized by means of generalized entropies of both the Rényi and Tsallis types. The Rényi and Tsallis formulations of uncertainty relations are obtained for both the scenarios of successive measurements of canonically conjugate operators. Entropic uncertainty relations for the cases of position and momentum are separately discussed. image