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Related papers: Impossible measurements revisited

200 papers

In quantum mechanics performing a measurement is an invasive process which generally disturbs the system. Due to this phenomenon, there exist incompatible quantum measurements, i.e., measurements that cannot be simultaneously performed on a…

Quantum Physics · Physics 2020-04-02 Sébastien Designolle , Máté Farkas , Jędrzej Kaniewski

Gathering data through measurements is at the basis of every experimental science. Ideally, measurements should be repeatable and, when extracting only coarse-grained data, they should allow the experimenter to retrieve the finer details at…

Quantum Physics · Physics 2014-04-21 G. Chiribella , X. Yuan

It is proposed a possible new approach of quantum measurements (QMS), disconnected of the traditional interpretation of uncertainty relations and independent of any appeal to the strange idea of collapse (reduction) of wave functions. The…

Quantum Physics · Physics 2007-05-23 S. Dumitru

We define nonlocal predictability as how well one observer can predict another's measurement outcomes without classical communication, given full knowledge of the shared quantum state and measurement settings. The local bound on nonlocal…

Quantum Physics · Physics 2026-02-19 Chirag Srivastava , Aparajita Bhattacharyya , Ujjwal Sen

An operational approach to quantum state reduction, the state change of the measured system caused by a measurement of an observable conditional upon the outcome of measurement, is founded without assuming the projection postulate in any…

Quantum Physics · Physics 2011-08-04 Masanao Ozawa

We introduce the concept of a "classical observable" as an operator with vanishingly small quantum fluctuations on a set of density matrices. It is shown how to construct them for a time evolved pure state. The study of classical…

Quantum Physics · Physics 2014-04-29 Michiel Wouters

In this Letter we investigate the concept of quantum work and its measurability from the viewpoint of quantum measurement theory. Very often, quantum work and fluctuation theorems are discussed in the framework of projective two-point…

Quantum Physics · Physics 2022-08-11 Konstantin Beyer , Roope Uola , Kimmo Luoma , Walter T. Strunz

Although nondemolition, reliable, and instantaneous quantum measurements of some nonlocal variables are impossible, demolition reliable instantaneous measurements are possible for all variables. It is shown that this is correct also in the…

Quantum Physics · Physics 2009-11-11 Lev Vaidman , Izhar Nevo

The Projection Postulate from Standard Quantum Mechanics relies fundamentally on measurements. But measurements implicitly suggest the existence of anthropocentric notions like measuring devices, which should rather emerge from the theory.…

Quantum Physics · Physics 2021-03-26 Ovidiu Cristinel Stoica

The notion that any physical quantity is defined and measured relative to a reference frame is traditionally not explicitly reflected in the theoretical description of physical experiments where, instead, the relevant observables are…

Quantum Physics · Physics 2016-03-25 Takayuki Miyadera , Leon Loveridge , Paul Busch

Pivotal within quantum physics, the concept of quantum incompatibility is generally related to algebraic aspects of the formalism, such as commutation relations and unbiasedness of bases. Recently, the concept was identified as a resource…

Quantum Physics · Physics 2020-12-24 E. Martins , M. F. Savi , R. M. Angelo

Quantum estimation theory provides optimal observations for various estimation problems for unknown parameters in the state of the system under investigation. However, the theory has been developed under the assumption that every observable…

Quantum Physics · Physics 2009-11-10 M. Hotta , M. Ozawa

We address the problem of reconstructing quantum theory from the perspective of an agent who makes bets about the outcomes of possible experiments. We build a general Bayesian framework that can be used to organize the agent's beliefs and…

Quantum Physics · Physics 2020-10-28 Giulio Chiribella , Adán Cabello , Matthias Kleinmann , Markus P. Müller

In the standard von Neumann interaction used in Quantum measurements, the chosen observable to which the environment (apparatus) entangles is exactly reproduced in the state of the environment, thereby decohering the quantum system in the…

Quantum Physics · Physics 2024-01-11 Adarsh S , P. N. Bala Subramanian , T. P. Sreeraj

The quantum nonlocality is limited by relativistic causality, however, the reason is not fully understood yet. The relativistic causality condition on nonlocal correlations has been usually accepted as a prohibition of faster-than-light…

Quantum Physics · Physics 2015-10-15 Yeong Deok Han , Taeseung Choi

We explore further the suggestion to describe a pre- and post-selected system by a two-state, which is determined by two conditions. Starting with a formal definition of a two-state Hilbert space and basic operations, we systematically…

Quantum Physics · Physics 2009-10-28 B. Reznik , Y. Aharonov

In physics we attempt to infer the rules governing a system given only the results of imprecise measurements. This is an ill-posed problem because certain features of the system's state cannot be resolved by the measurements. However, by…

Quantum Physics · Physics 2014-04-03 Cédric Bény , Tobias J. Osborne

Any realist interpretation of quantum theory must grapple with the measurement problem and the status of state-vector collapse. In a no-collapse approach, measurement is typically modeled as a dynamical process involving decoherence. We…

Quantum Physics · Physics 2020-09-22 Jacob A. Barandes , David Kagan

The notion of weak measurement provides a formalism for extracting information from a quantum system in the limit of vanishing disturbance to its state. Here we extend this formalism to the measurement of sequences of observables. When…

Quantum Physics · Physics 2009-11-13 Graeme Mitchison , Richard Jozsa , Sandu Popescu

I introduce a framework to distinguish two domains of physics - the manifest (i.e. the directly observable empirical records in terms of manifest configurations) and the non-manifest domain of physics (i.e. the things that the manifest…

Quantum Physics · Physics 2024-08-13 Johannes Fankhauser