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Related papers: Repeatable measurements and the collapse postulate

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The uncertainty associated with probing the quantum state is expressed as the effective abundance (measure) of possibilities for its collapse. New kinds of uncertainty limits entailed by quantum description of the physical system arise in…

Quantum Physics · Physics 2019-07-12 Ivan Horváth , Robert Mendris

The postulates of von Neumann and L\"uders concerning measurements in quantum mechanics are discussed and criticized in the context of a simple model proposed by Gisin. The main purpose of our paper is to analyze some mathematical aspects…

Quantum Physics · Physics 2022-12-07 Jürg Fröhlich , Zhou Gang

The usual conjectures of quantum measurements approaches, inspired from the traditional interpretation of Heisenberg's ("uncertainty") relations, are proved as being incorrect. A group of reconsidered conjectures and a corresponding new…

Quantum Physics · Physics 2007-05-23 Spiridon Dumitru

In this work we study the phenomenon of self-testing from the first principles, aiming to place this versatile concept on a rigorous mathematical footing. Self-testing allows a classical verifier to infer a quantum mechanical description of…

The problem of measurement is often considered as an inconsistency inside the quantum formalism. Many attempts to solve (or to dissolve) it have been made since the inception of quantum mechanics. The form of these attempts depends on the…

Quantum Physics · Physics 2016-04-20 Herve Zwirn

A fundamental prediction of quantum theory that is derived from the "projection postulate" is that under continuous measurement, the state of a system traces out a "quantum trajectory" in time that depends upon its measurement record, and…

Quantum Physics · Physics 2014-01-03 A. A. Gangat

A general scheme is presented for controlling quantum systems using evolution driven by non-selective von Neumann measurements, with or without an additional tailored electromagnetic field. As an example, a 2-level quantum system controlled…

Quantum Physics · Physics 2007-05-23 Alexander Pechen , Nikolai Il'in , Feng Shuang , Herschel Rabitz

Quantum measurement finds the observed system in a collapsed state, rather than in the state predicted by the Schr\"odinger equation. Yet there is a relatively spread opinion that the wavefunction collapse can be explained by unitary…

Quantum Physics · Physics 2016-02-08 Ovidiu Cristinel Stoica

Theory of quantum measurements is often classified as decision theory. An event in decision theory corresponds to the measurement of an observable. This analogy looks clear for operationally testable simple events. However, the situation is…

Quantum Physics · Physics 2015-06-24 V. I. Yukalov , D. Sornette

The so-called quantum measurement problems are solved from a new perspective. One of the main observations is that the basic entities of our world are {\it particles}, elementary or composite. It follows that each elementary process, hence…

Quantum Physics · Physics 2023-02-20 Kenichi Konishi

Wavefunction collapse is usually seen as a discontinuous violation of the unitary evolution of a quantum system, caused by the observation. Moreover, the collapse appears to be nonlocal in a sense which seems at odds with General…

Quantum Physics · Physics 2016-01-12 Ovidiu Cristinel Stoica

We exhibit three inequalities involving quantum measurement, all of which are sharp and state independent. The first inequality bounds the performance of joint measurement. The second quantifies the trade-off between the measurement quality…

Quantum Physics · Physics 2021-08-18 Bas Janssens

The entangled Schrodinger cat state obtained immediately upon measurement of a superposed two-state quantum system is often considered paradoxical because it appears to predict two macroscopically different outcomes, such as an alive and…

Quantum Physics · Physics 2022-06-14 Art Hobson

Notwithstanding it is well known that von Neumann's projection postulate is inapplicable to most realistic measurement procedures, it keeps haunting the foundations of quantum mechanics. In particular its applicability to EPR experiments is…

Quantum Physics · Physics 2009-11-13 Willem M. de Muynck

This essay aims to propose construction theory, a new domain of theoretical research on machine construction, and use it to shed light on a fundamental relationship between living and computational systems. Specifically, we argue that…

Adaptation and Self-Organizing Systems · Physics 2009-09-29 Hiroki Sayama

Left on its own, a quantum state evolves deterministically under the Schr\"odinger Equation, forming superpositions. Upon measurement, however, a stochastic process governed by the Born rule collapses it to a single outcome. This dual…

Quantum Physics · Physics 2026-01-01 Anderson A. Tomaz , Rafael S. Mattos , Mario Barbatti

It was argued [1] that there can be no extension of quantum mechanics with improved predictive power on a measurement freely chosen, independently of any event that is not in its future light cone. The assumption of measurement choice was…

Quantum Physics · Physics 2025-12-09 Yiruo Lin

The existence of incompatible measurements, epitomized by Heisenberg's uncertainty principle, is one of the distinctive features of quantum theory. So far, quantum incompatibility has been studied for measurements that test the preparation…

Quantum Physics · Physics 2017-03-16 Michal Sedlak , Daniel Reitzner , Giulio Chiribella , Mario Ziman

The nRules are empirical regularities that were discovered in macroscopic situations where the outcome is known. When they are projected theoretically into the microscopic domain they predict a novel ontology including the frequent collapse…

Quantum Physics · Physics 2009-11-13 Richard A Mould

Two hallmarks of quantum non-demolition (QND) measurement are the ensemble-level conservation of the expectation value of the measured observable $A$ and the eventual, inevitable collapse of the system into some eigenstate of $A$. This…

Quantum Physics · Physics 2025-05-07 Carter Swift , Nandini Trivedi