English
Related papers

Related papers: Can the Quantum Measurement Problem be resolved wi…

200 papers

We provide an alternative approach to the decoherence-by-environment paradigm in the field of the quantum measurement process and the appearance of a classical world. In contrast to the decoherence approach we argue that the transition from…

Quantum Physics · Physics 2012-02-29 Manfred Requardt

During a continuous measurement, quantum systems can be described by a stochastic Schr\"odinger equation which, in the appropriate limit, reproduces the von Neumann wave-function collapse. The average behavior on the ensemble of all…

Condensed Matter · Physics 2009-10-30 Carlo Presilla , Ubaldo Tanbini

Quantum observables can be identified with vector fields on the sphere of normalized states. The resulting vector representation is used in the paper to undertake a simultaneous treatment of macroscopic and microscopic bodies in quantum…

Quantum Physics · Physics 2017-10-04 Alexey A. Kryukov

Stochastic extensions of the Schrodinger equation have attracted attention recently as plausible models for state reduction in quantum mechanics. Here we formulate a general approach to stochastic Schrodinger dynamics in the case of a…

Quantum Physics · Physics 2015-06-26 D. C. Brody , L. P. Hughston

A brief review is given of the present state of an approach to consistency between basic quantum mechanics and a unique macroscopic reality, with no assumption of branching in the state of the universe. The main new idea consists in the…

Quantum Physics · Physics 2013-02-08 Roland Omnes

A quantum many-body model is presented with features similar to those of certain particle detectors. The energy spectrum contains a single metastable 'ready'-state and macroscopically-distinct 'pointer' states. Measurements do not pose…

Quantum Physics · Physics 2007-05-23 R. Merlin

We propose a new model for a measurement of a characteristic of a microscopic quantum state by a large system that selects stochastically the different eigenstates with appropriate quantum weights. Unlike previous works which formulate a…

Quantum Physics · Physics 2009-01-24 Fariel Shafee

It is shown that it is possible to measure the Schr\"odinger wave of a single quantum system. This provides a strong argument for associating physical reality with a quantum state of a single system in sharp contrast with the usual approach…

High Energy Physics - Theory · Physics 2007-05-23 Yakir Aharonov , Lev Vaidman

We present a framework that formulates the quest for the most efficient quantum state tomography scheme as an optimization problem which can be solved numerically. This approach can be applied to a broad spectrum of relevant setups…

Quantum Physics · Physics 2021-12-17 Violeta N. Ivanova-Rohling , Guido Burkard , Niklas Rohling

We present an exact derivation of a process in which a microscopic measured system interacts with heat-bath and pointer modes of a measuring device, via a coupling involving a general Hermitian operator $\Lambda$ of the system. In the limit…

Mesoscale and Nanoscale Physics · Physics 2016-08-31 Dima Mozyrsky , Vladimir Privman

Characterizing complex quantum systems is a vital task in quantum information science. Quantum tomography, the standard tool used for this purpose, uses a well-designed measurement record to reconstruct quantum states and processes. It is,…

Quantum Physics · Physics 2015-12-10 Amir Kalev , Robert L. Kosut , Ivan H. Deutsch

Let S be the von Neumann entropy of a finite ensemble E of pure quantum states. We show that S may be naturally viewed as a function of a set of geometrical volumes in Hilbert space defined by the states and that S is monotonically…

Quantum Physics · Physics 2009-11-10 Graeme Mitchison , Richard Jozsa

A pair of conjugate observables, such as the quadrature amplitudes of harmonic motion, have fundamental fluctuations which are bound by the Heisenberg uncertainty relation. However, in a squeezed quantum state, fluctuations of a quantity…

Mesoscale and Nanoscale Physics · Physics 2015-12-16 J. -M. Pirkkalainen , E. Damskägg , M. Brandt , F. Massel , M. A. Sillanpää

The quantum measurement problem as was formulated by von Neumann in 1933 can be solved by going beyond the operational quantum formalism. In our "prequantum model" quantum systems are symbolic representations of classical random fields. The…

Quantum Physics · Physics 2015-06-12 Andrei Khrennikov

An emergent theory of quantum measurement arises directly by considering the particular subset of many body wavefunctions that can be associated with classical condensed matter and its interaction with delocalized wavefunctions. This…

Quantum Physics · Physics 2015-03-03 Clifford Chafin

Quantum mechanics introduces the concept of probability at the fundamental level, yielding the measurement problem. On the other hand, recent progress in cosmology has led to the "multiverse" picture, in which our observed universe is only…

High Energy Physics - Theory · Physics 2012-05-10 Yasunori Nomura

A quantum measuring instrument is constructed that utilises symmetry breaking to enhance a microscopic signal. The entire quantum system consists of a system-apparatus-environment triad that is composed of a small set of spin-1/2 particles.…

Quantum Physics · Physics 2018-08-07 H. C. Donker , H. De Raedt , M. I. Katsnelson

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 a quantum measurement, a coupling $g$ between the system S and the apparatus A triggers the establishment of correlations, which provide statistical information about S. Robust registration requires A to be macroscopic, and a dynamical…

Quantum Physics · Physics 2015-06-26 Armen E. Allahverdyan , Roger Balian , Theo M. Nieuwenhuizen

Beyond their use as numerical tools, quantum trajectories can be ascribed a degree of reality in terms of quantum measurement theory. In fact, they arise naturally from considering continuous observation of a damped quantum system. A…

Quantum Physics · Physics 2009-11-10 H. M. Wiseman