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Related papers: Partial Measurements of Quantum Systems

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We use continuous, stochastic quantum trajectories within a framework of quantum state diffusion (QSD) to describe alternating measurements of two non-commuting observables. Projective measurement of an observable completely destroys memory…

Quantum Physics · Physics 2024-09-24 Sophia M. Walls , Ian J. Ford

In this tutorial, we present the definition, interpretation and properties of some of the main quasiprobabilities that can describe the statistics of measurement outcomes evaluated at two or more times. Such statistics incorporate the…

Quantum Physics · Physics 2024-09-23 Stefano Gherardini , Gabriele De Chiara

For a quantum system undergoing a unitary process work is commonly defined based on the Two Projective Measurement (TPM) protocol which measures the energies of the system before and after the process. However, it is well known that…

Quantum Physics · Physics 2017-11-22 P. Solinas , H. J. D. Miller , J. Anders

The systematical studies on the dynamical approach of wavefunction collapse in quantum measurement are reported in this paper based on the Hepp-Coleman's model and its generalizations. Under certain physically reasonable conditions, which…

High Energy Physics - Theory · Physics 2009-10-28 Chang-Pu Sun

Incompatibility of certain measurements -- impossibility of obtaining deterministic outcomes simultaneously -- is a well known property of quantum mechanics. This feature can be utilized in many contexts, ranging from Bell inequalities to…

Quantum Physics · Physics 2018-03-14 Martin Plesch , Matej Pivoluska

We suggest a general scheme for quantum state engineering based on conditional measurements carried out on entangled twin-beam of radiation. Realistic detection schemes such as {\sc on/off} photodetection, homodyne detection and joint…

Quantum Physics · Physics 2009-11-07 Matteo G. A. Paris , Mary Cola , Rodolfo Bonifacio

A new, realist interpretation of the quantum measurement processes is given. In this scenario a quantum measurement is a non-equilibrium phase transition in a ``resonant cavity'' formed by the entire physical universe including all its…

Quantum Physics · Physics 2009-11-13 Xiaolei Zhang

Measurement uncertainty and experimental error are important concepts taught in undergraduate physics laboratories. Although student ideas about error and uncertainty in introductory classical mechanics lab experiments have been studied…

Physics Education · Physics 2021-09-20 Emily M. Stump , Courtney L. White , Gina Passante , N. G. Holmes

We consider highly inaccurate measurements made on classical stochastic and quantum systems. In the quantum case such a \e{weak} measurement preserves coherence between the system's alternatives. We demonstrate that in both cases the…

Quantum Physics · Physics 2026-03-16 D. Sokolovski , D. Alonso , S. Brouard

Quantum measurements and phase transitions are seemingly uncorrelated topics, but here we show that phase transitions occur in sequential quantum measurements. We find that the probability distribution of the measurement results of a…

Quantum Physics · Physics 2018-07-17 Wen-Long Ma , Ping Wang , Weng-Hang Leong , Ren-Bao Liu

In this paper, we present a collection of results on the observability of quantum mechanical systems, in the case the output is the result of a discrete nonselective measurement. By defining an effective observable we extend previous…

Quantum Physics · Physics 2007-05-23 D. D'Alessandro , R. Romano

In this paper, we present a thought experiment that demonstrates that the equivalence of quantum reduced states and statistical mixed states of ensembles is not merely a simple mathematical formulation in quantum mechanics, but rather…

Quantum Physics · Physics 2025-04-18 Zhihong Zuo

We consider the effect of projective measurements on the quench dynamics of the bipartite entanglement entropy in one dimensional free fermionic systems. In our protocol, we consider projective measurements of a $U(1)$ conserved charge, the…

Quantum Physics · Physics 2025-12-15 Riccardo Travaglino , Colin Rylands , Pasquale Calabrese

This article sets up a new formalism to investigate stochastic thermodynamics in the quantum regime, where stochasticity and irreversibility primarily come from quantum measurement. In the absence of any bath, we define a purely quantum…

Quantum Physics · Physics 2017-03-16 Cyril Elouard , David Herrera-Martí , Maxime Clusel , Alexia Auffèves

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

Quantum measurements can be incompatible, i.e., they can fail to be jointly measurable. Recently, a weaker notion of joint-measurability, called partial joint-measurability, was proposed by Masini et al. in [Quantum 8, 1574 (2024)]. In this…

Quantum Physics · Physics 2026-05-18 Edwin Peter Lobo , Maria Balanzó-Juandó , Stefano Pironio

We explore the measurement problem in the entropic dynamics approach to quantum theory. The dual modes of quantum evolution---either continuous unitary evolution or abrupt wave function collapse during measurement---are unified by virtue of…

Quantum Physics · Physics 2015-05-30 David T. Johnson , Ariel Caticha

A long-standing quantum-mechanical puzzle is whether the collapse of the wave function is a real physical process or simply an epiphenomenon. This puzzle lies at the heart of the measurement problem. One way to choose between the…

Quantum Physics · Physics 2016-12-23 A. Yu. Ignatiev

We present a scheme to estimate Gaussian states of one-dimensional continuous variable systems, based on weak (unsharp) quantum measurements. The estimation of a Gaussian state requires us to find position ($q$), momentum ($p$) and their…

Quantum Physics · Physics 2017-04-05 Debmalya Das , Arvind

Quantum measurement is a fundamental concept in the field of quantum mechanics. The action of quantum measurement, leading the superposition state of the measured quantum system into a definite output state, not only reconciles…

General Physics · Physics 2024-08-13 Wei Wen