English
Related papers

Related papers: Quantum and classical descriptions of a measuring …

200 papers

Some of the most enduring questions in physics--including the quantum measurement problem and the quantization of gravity--involve the interaction of a quantum system with a classical environment. Two linearly coupled harmonic oscillators…

Quantum Physics · Physics 2007-05-23 Rachael M. McDermott , Ian H. Redmount

Quantum instruments are mathematical devices introduced to describe the conditional state change during a quantum process. They are completely positive map valued measures on measurable spaces. We may also view them as non-commutative…

Operator Algebras · Mathematics 2025-09-17 B. V. Rajarama Bhat , Arghya Chongdar , Sruthymurali

This work will incorporate a few related tools for addressing the conceptual difficulties arising from sewing together classical and quantum mechanics: deterministic operators, weak measurements and post-selection. Weak Measurement, based…

Quantum Physics · Physics 2016-12-21 Eliahu Cohen , Yakir Aharonov

In the classical world one can construct two identical systems which have identical behavior and give identical measurement results. We show this to be impossible in the quantum domain. We prove that after the same quantum measurement two…

Quantum Physics · Physics 2017-01-10 Denis Sych , Gerd Leuchs

Recently a study of the first superposed mechanical quantum object ("machine") visible to the naked eye was published. However, as we show, it turns out that if the object would actually be observed, i.e. would interact with an optical…

General Physics · Physics 2015-04-01 Johan Hansson

Classical dynamics is formulated as a Hamiltonian flow on phase space, while quantum mechanics is formulated as a unitary dynamics in Hilbert space. These different formulations have made it difficult to directly compare quantum and…

Quantum Physics · Physics 2007-05-23 A. J. Scott , G. J. Milburn

This paper is a review of our recent work on three notorious problems of non-relativistic quantum mechanics: realist interpretation, quantum theory of classical properties and the problem of quantum measurement. A considerable progress has…

Quantum Physics · Physics 2013-03-01 Petr Hajicek

In quantum information processing quantum operations are often processed alongside measurements which result in classical data. Due to the information gain of classical measurement outputs non-unitary dynamical processes can take place on…

The measurement problem in quantum mechanics originates in the inability of the Schr\"odinger equation to predict definite outcomes of measurements. This is due to the lack of objectivity of the eigenstates of the measuring apparatus. Such…

Quantum Physics · Physics 2017-05-26 Partha Ghose

Both classical and respectively quantum observables can be modeled as somewhat similar examples of random variables. In such a model the associated measurements preserve the values spectrum of an observable but change the corresponding…

Statistical Mechanics · Physics 2008-03-20 S. Dumitru , A. Boer

Measurement is an important scientific activity. In most of science, including classical physics, is may be understood as a way of finding out about the physical world and representing the results numerically. No-go theorems show that…

Quantum Physics · Physics 2026-05-18 Richard Healey

Quantum simulators are devices that actively use quantum effects to answer questions about model systems and, through them, real systems. Here we expand on this definition by answering several fundamental questions about the nature and use…

Quantum Physics · Physics 2014-07-28 T. H. Johnson , S. R. Clark , D. Jaksch

A model of quantum measurement is proposed, which aims to describe statistical mechanical aspects of this phenomenon, starting from a purely Hamiltonian formulation. The macroscopic measurement apparatus is modeled as an ideal Bose gas, the…

Statistical Mechanics · Physics 2016-08-31 Armen E. Allahverdyan , Roger Balian , Theo M. Nieuwenhuizen

A consistent description of interactions between classical and quantum systems is relevant to quantum measurement theory, and to calculations in quantum chemistry and quantum gravity. A solution is offered here to this longstanding problem,…

Quantum Physics · Physics 2009-11-11 Michael J. W. Hall , Marcel Reginatto

We give a review of concepts related to connection of classical and quantum theories, from the phase space perspective. Quantum theory is described by non-commutative operators of coordinates and momenta, results in values having a certain…

Quantum Physics · Physics 2025-09-04 Miloš D. Davidović , Ljubica D. Davidović , Milena D. Davidović

We take the view that physical quantities are values generated by processes in measurement, not pre-existent objective quantities, and that a measurement result is strictly a product of the apparatus and the subject of the measurement. We…

General Physics · Physics 2007-05-23 Charles Francis

We propose a system of equations to describe the interaction of a quasiclassical variable $X$ with a set of quantum variables $x$ that goes beyond the usual mean field approximation. The idea is to regard the quantum system as continuously…

Quantum Physics · Physics 2009-10-30 L. Diosi , J. J. Halliwell

The measurement of a quantum system becomes itself a quantum-mechanical process once the apparatus is internalized. That shift of perspective may result in different physical predictions for a variety of reasons. We present a model…

Mathematical Physics · Physics 2019-08-28 Martin Fraas , Gian Michele Graf , Lisa Hänggli

Quantum mechanics is usually presented starting from a series of postulates about the mathematical framework. In this work we show that those same postulates can be derived by assuming that measurements are discrete interactions: that is,…

Quantum Physics · Physics 2008-01-08 Gabriele Carcassi

A quantum system at equilibrium is represented by a corresponding classical system, chosen to reproduce the thermodynamic and structural properties. The objective is to develop a means for exploiting strong coupling classical methods (e.g.,…

Statistical Mechanics · Physics 2015-05-30 James W. Dufty , Sandipan Dutta