English
Related papers

Related papers: Conditioned Observables in Quantum Mechanics

200 papers

A suggestion for an observational test of the difference between quantum mechanics and noncontextual hidden variables theories requires the measurement of a product of two commuting observables without measuring either observable…

Quantum Physics · Physics 2007-05-23 R. L. Schafir

An extension of the conditional expectations (those under a given subalgebra of events and not the simple ones under a single event) from the classical to the quantum case is presented. In the classical case, the conditional expectations…

Mathematical Physics · Physics 2010-01-22 Gerd Niestegge

We consider in general terms dynamical systems with finite-dimensional, non-simply connected configuration-spaces. The fundamental group is assumed to be finite. We analyze in full detail those ambiguities in the quantization procedure that…

Quantum Physics · Physics 2007-05-23 Domenico Giulini

The quantum dynamics of optomechanical systems was mostly studied for their fluctuations around classical steady states. We present a theoretical approach to determining the system observables of optomechanical systems as genuine quantum…

Quantum Physics · Physics 2012-06-21 Bing He

Quantum measurements of physical quantities are usually described as ideal measurements. However, only a few measurements fulfil the conditions of ideal measurements. The aim of the present work is to describe real position measurements…

Quantum Physics · Physics 2019-01-17 Klaus Wick

Uncertainty principle is one of the cornerstones of quantum theory. In the literature, there are two types of uncertainty relations, the operator form concerning the variances of physical observables and the entropy form related to entropic…

Quantum Physics · Physics 2015-09-18 Jun-Li Li , Cong-Feng Qiao

A measurement model is a framework that describes a quantum measurement process. In this article we restrict attention to $MM$s on finite-dimensional Hilbert spaces. Suppose we want to measure an observable $A$ whose outcomes $A_x$ are…

Quantum Physics · Physics 2020-09-29 Stan Gudder

The origin of non-classical correlations is difficult to identify since the uncertainty principle requires that information obtained about one observable invariably results in the disturbance of any other non-commuting observable. Here,…

Quantum Physics · Physics 2014-07-01 Holger F. Hofmann

We discuss the construction of relational observables in time-reparametrization invariant quantum mechanics and we argue that their physical interpretation can be understood in terms of conditional probabilities, which are defined from the…

General Relativity and Quantum Cosmology · Physics 2021-01-21 Leonardo Chataignier

Quantum coherence, a basic feature of quantum mechanics residing in superpositions of quantum states, is a resource for quantum information processing. Coherence emerges in a fundamentally different way for nonidentical and identical…

For an arbitrary preparation, quantum mechanical descriptions refer to the complementary contexts set by incompatible measurements. We argue that an arbitrary preparation, therefore, should be described with respect to such a context by its…

Quantum Physics · Physics 2009-11-10 Mohammad Mehrafarin

Quantum mechanics, in principle, allows for processes with indefinite causal order. However, most of these causal anomalies have not yet been detected experimentally. We show that every such process can be simulated experimentally by means…

Quantum Physics · Physics 2018-04-04 Simon Milz , Felix A. Pollock , Thao P. Le , Giulio Chiribella , Kavan Modi

In this paper we provide a method for constructing joint distributions for an arbitrary set of observables on finite dimensional Hilbert spaces irrespective of whether the observables commute or not. These distributions have a number of…

Quantum Physics · Physics 2016-10-27 Todd A. Oliynyk

In one-dimensional case, it is shown that the basic principles of quantum mechanics are properties of the set of intermediate cardinality.

Quantum Physics · Physics 2007-05-23 O. Yaremchuk

In Quantum Physics there are circumstances where the direct measurement of particular observables encounters diffculties; in some of these cases, however, its value can be evaluated, i.e. it can be inferred by measuring another observable…

Quantum Physics · Physics 2016-03-23 Giuseppe Nisticò , Angela Sestito

Modelling quantum devices is to find a model according to quantum theory that can explain the result of experiments in a quantum device. We find that usually we cannot correctly identify the model describing the actual physics of the device…

Quantum Physics · Physics 2019-10-08 Hang Ren , Ying Li

We consider three types of entities for quantum measurements. In order of generality, these types are: observables, instruments and measurement models. If $\alpha$ and $\beta$ are entities, we define what it means for $\alpha$ to be a part…

Quantum Physics · Physics 2022-09-01 Stan Gudder

There are two major approaches to building good machine learning algorithms: feeding lots of data into large models, or picking a model class with an ''inductive bias'' that suits the structure of the data. When taking the second approach…

Quantum Physics · Physics 2023-12-08 Kaitlin Gili , Guillermo Alonso , Maria Schuld

The probability `measure' for measurements at two consecutive moments of time is non-additive. These probabilities, on the other hand, may be determined by the limit of relative frequency of measured events, which are by nature additive. We…

Quantum Physics · Physics 2009-11-10 Charis Anastopoulos

We investigate what can be concluded about a quantum system when sequential quantum measurements of its observable -- a prominent example of the so-called quantum stochastic process -- fulfill the Kolmogorov consistency condition and thus…

Quantum Physics · Physics 2024-07-02 Piotr Szańkowski , Łukasz Cywiński