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Related papers: Weak Values as Context Dependent Values of Observa…

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We refute the widely held belief that the quantum weak value necessarily pertains to weak measurements. To accomplish this, we use the transverse position of a beam as the detector for the conditioned von Neumann measurement of a system…

Quantum Physics · Physics 2013-01-16 J. Dressel , A. N. Jordan

Born's rule is the recipe for calculating probabilities from quantum mechanical amplitudes. There is no generally accepted derivation of Born's rule from first principles. In this paper, it is motivated from assumptions that link the…

Quantum Physics · Physics 2024-11-05 Per Östborn

The presence of contextuality in quantum theory was first highlighted by Bell, Kochen and Specker, who discovered that for quantum systems of three or more dimensions, measurements cannot be viewed as revealing pre-existing properties of…

Quantum Physics · Physics 2017-04-07 Andrew W. Simmons , Joel J. Wallman , Hakop Pashayan , Stephen D. Bartlett , Terry Rudolph

The quantum mechanical weak value $A_w=\left\langle \phi|A|\psi \right \rangle / \left\langle \phi | \psi \right\rangle$ of an observable $A$ is a measurable quantity associated with an observable $A$ and pre- and post-selected states…

Quantum Physics · Physics 2023-10-27 Rafael Wagner , Ernesto F. Galvão

A recent Letter in Physical Review Letters, "Contextual Values of Observables in Quantum Measurements", by J. Dressel, S. Agarwal, and A. N. Jordan (abbreviated DAJ below), introduces the concept of "contextual values" and claims that they…

Quantum Physics · Physics 2011-05-24 Stephen Parrott

Weak measurements introduced by Aharonov, Albert and Vaidman (AAV) can provide informations about the system with minimal back action. Weak values of product observables (commuting) or higher moments of an observable are informationally…

Quantum Physics · Physics 2023-09-13 Sahil , Sohail , Subhrajit Modak , Sibasish Ghosh , Arun Kumar Pati

"Weak measurements" -- involving a weak unitary interaction between a quantum system and a meter followed by a projective measurement -- are investigated when the system has a non-Hermitian Hamiltonian. We show in particular how the…

Quantum Physics · Physics 2012-12-21 A. Matzkin

The readings of a highly inaccurate "weak" quantum meter, employed to determine the value of a dichotomous variable $S$ without destroying the interference between the alternatives,may take arbitrary values. We show that the expected values…

Quantum Physics · Physics 2015-09-17 D. Sokolovski

The Schr{\"o}dinger inequality is known to underlie the Kennard-Robertson inequality, which is the standard expression of quantum uncertainty for the product of variances of two observables $A$ and $B$, in the sense that the latter is…

Quantum Physics · Physics 2020-08-10 Jaeha Lee , Keita Takeuchi , Kaisei Watanabe , Izumi Tsutsui

A non-relativistic quantum mechanical theory is proposed that describes the universe as a continuum of worlds whose mutual interference gives rise to quantum phenomena. A logical framework is introduced to properly deal with propositions…

Quantum Physics · Physics 2015-08-18 Kim Joris Boström

Weak values are usually associated with weak measurements of an observable on a pre- and post-selected ensemble. We show that more generally, weak values are proportional to the correlation between two pointers in a successive measurement.…

Quantum Physics · Physics 2009-08-03 Lars M. Johansen , Pier A. Mello

We present a systematic procedure to obtain all necessary and sufficient (quantum) constraints on the expectation values for any set of qudit's operators. These constraints---arise form Hermiticity, normalization, and positivity of a…

Quantum Physics · Physics 2018-05-14 Arun Sehrawat

The variance of an arbitrary pointer observable is considered for the general case that a complex weak value is measured using a complex valued pointer state. For the typical cases where the pointer observable is either its position or…

Quantum Physics · Physics 2015-05-27 A. D. Parks , J. E. Gray

A precise definition of "weak [quantum] measurements" and "weak value" (of a quantum observable) is offered, and simple finite dimensional examples are given showing that weak values are not unique and therefore probably do not correspond…

Quantum Physics · Physics 2009-10-01 Stephen Parrott

Quantum mechanics traditionally places the observer outside of the system being studied and employs the Born interpretation. In this and related papers the observer is placed inside the system. To accomplish this, special rules are required…

General Physics · Physics 2007-05-23 Richard A. Mould

Weak values arise experimentally as conditioned averages of weak (noisy) observable measurements that minimally disturb an initial quantum state, and also as dynamical variables for reduced quantum state evolution even in the absence of…

Quantum Physics · Physics 2015-03-20 Justin Dressel

A so called 'weak value' of an observable in quantum mechanics (QM) may be obtained in a weak measurement + post-selection procedure on the QM system under study. Applied to number operators, it has been invoked in revisiting some QM…

Quantum Physics · Physics 2015-06-12 Bengt E Y Svensson

The AAV effect is the well-known phenomenon where a weak measurement followed by post-selection leads to a pointer shift proportional to the weak value of the measured observable. The effect is usually derived by considering a perturbative…

Quantum Physics · Physics 2014-06-04 Jeff Z. Salvail

Quantum mechanics does not permit joint measurements of non-commuting observables. However, it is possible to measure the weak value of a projection operator, followed by the precise measurement of a different property. The results can be…

Quantum Physics · Physics 2015-02-25 Holger F. Hofmann

The notion of state vector is, in quantum mechanics, as central as it is problematic, as illustrates the wealth of publications about the sub- jects, including in particular the many attempts to obtain an acceptable interpretation of…

Quantum Physics · Physics 2013-05-07 Olivier Brunet