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In the weak measurement formalism of Y. Aharonov et al. the so-called weak value A_w of any observable A is generally a complex number. We derive a physical interpretation of its value in terms of the shift in the measurement pointer's mean…

Quantum Physics · Physics 2009-11-13 Richard Jozsa

Results of measurements give legitimacy to a physical theory. What if acquiring these results in the first place necessitates what the same theory considers to be an interaction? In this note, we assume that theories account for…

Quantum Physics · Physics 2019-05-01 Arne Hansen , Stefan Wolf

Quantum contextuality represents a fundamental form of nonclassicality in quantum mechanics. To provide a more complete characterization of nonclassical properties in quantum systems, we adopt a logical perspective and propose a…

Quantum Physics · Physics 2025-12-03 Songyi Liu , Yongjun Wang , Baoshan Wang , Chang He , Jincheng Wang

Contextuality has long been associated with topological properties. In this work, such a relationship is elevated to identification in the broader framework of generalized contextuality. We employ the usual identification of states,…

Quantum Physics · Physics 2024-07-04 Sidiney B. Montanhano

Recently it has been proposed, using the formalism of positive-operator-valued measures, a possible definition of quantum coordinates for events in the context of quantum mechanics. In this short note we analyze this definition from the…

Quantum Physics · Physics 2009-10-31 Riccardo Giannitrapani

Under the principle that quantum mechanical observables are invariant under relevant symmetry transformations, we explore how the usual, non-invariant quantities may capture measurement statistics. Using a relativisation mapping, viewed as…

Quantum Physics · Physics 2017-04-05 Leon Loveridge , Paul Busch , Takayuki Miyadera

The existence of incompatible measurements is often believed to be a feature of quantum theory which signals its inconsistency with any classical worldview. To prove the failure of classicality in the sense of Kochen-Specker…

Quantum Physics · Physics 2024-04-05 John H. Selby , David Schmid , Elie Wolfe , Ana Belén Sainz , Ravi Kunjwal , Robert W. Spekkens

The ideas of Sensible Quantum Mechanics are expressed in lay terms for philosophers of consciousness and others. A framework is proposed and explained for the `psycho-physical-parallelism' between conscious experiences and the mathematical…

Quantum Physics · Physics 2007-05-23 Don N. Page

Random variables representing measurements, broadly understood to include any responses to any inputs, form a system in which each of them is uniquely identified by its content (that which it measures) and its context (the conditions under…

Quantum Physics · Physics 2019-01-24 Ehtibar N. Dzhafarov , Víctor H. Cervantes , Janne V. Kujala

We address the issue of how to properly treat, and in a more general setting, the concept of a weak value of a weak measurement in quantum mechanics. We show that for this purpose, one must take in account the effects of the measuring…

Quantum Physics · Physics 2009-07-24 A. C. Lobo , C. A. Ribeiro

One of the central foundational questions of physics is to identify what makes a system quantum as opposed to classical. One seminal notion of classicality of a quantum system is the existence of a non-contextual hidden variable model as…

Quantum Physics · Physics 2022-01-03 Jonas Haferkamp , Juani Bermejo-Vega

We introduce an equivariant version of contextuality with respect to a symmetry group, which comes with natural applications to quantum theory. In the equivariant setting, we construct cohomology classes that can detect contextuality. This…

Quantum Physics · Physics 2023-10-30 Cihan Okay , Igor Sikora

Physical entities are ultimately (re)constructed from elementary yes/no events, in particular clicks in detectors or measurement devices recording quanta. Recently, the interpretation of certain such clicks has given rise to unfounded…

Quantum Physics · Physics 2012-03-02 Karl Svozil

Quantum computing is usually associated with discrete quantum states and physical quantities possessing discrete eigenvalue spectrum. However, quantum computing in general is any computation accomplished by the exploitation of quantum…

Quantum Physics · Physics 2021-07-06 Samantha Buck , Robin Coleman , Hayk Sargsyan

An analysis of errors in measurement yields new insight into the penetration of quantum particles into classically forbidden regions. In addition to ``physical" values, realistic measurements yield ``unphysical" values which, we show, can…

High Energy Physics - Theory · Physics 2009-10-22 Y. Aharonov , S. Popescu , D. Rohrlich , L. Vaidman

We develop a notion of quantum observable for the general boundary formulation of quantum theory. This notion is adapted to spacetime regions rather than to hypersurfaces and naturally fits into the topological quantum field theory like…

High Energy Physics - Theory · Physics 2012-09-06 Robert Oeckl

A relation is obtained between weak values of quantum observables and the consistency criterion for histories of quantum events. It is shown that ``strange'' weak values for projection operators (such as values less than zero) always…

Quantum Physics · Physics 2007-05-23 R. E. Kastner

Physical interpretations of the time-symmetric formulation of quantum mechanics, due to Aharonov, Bergmann, and Lebowitz are discussed in terms of weak values. The most direct, yet somewhat naive, interpretation uses the time-symmetric…

Quantum Physics · Physics 2022-01-25 Mordecai Waegell , Eliahu Cohen , Avshalom Elitzur , Jeff Tollaksen , Yakir Aharonov

Fully revealing the mathmatical structure of quantum contextuality is a significant task, while some known contextuality theories are only applicable for rank-1 projectors. That is because they adopt the observable-based definitions. This…

Quantum Physics · Physics 2025-01-17 Songyi Liu , Yongjun Wang , Baoshan Wang , Yunyi Jia

An operational definition of contextuality is introduced which generalizes the standard notion in three ways: (1) it applies to arbitrary operational theories rather than just quantum theory, (2) it applies to arbitrary experimental…

Quantum Physics · Physics 2016-09-08 R. W. Spekkens