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We describe a technique for self consistently characterizing both the quantum state of a single qubit system, and the positive-operator-valued measure (POVM) that describes measurements on the system. The method works with only ten…

Quantum Physics · Physics 2021-07-28 A. Stephens , J. M. Cutshall , T. McPhee , M. Beck

We consider the decomposition of bounded linear operators on Hilbert spaces in terms of functions forming frames. Similar to the singular-value decomposition, the resulting frame decompositions encode information on the structure and…

Numerical Analysis · Mathematics 2021-05-26 Simon Hubmer , Ronny Ramlau

In this work, we show that the quantum mechanical notions of density operator, positive operator-valued measure (POVM), and the Born rule, are all simultaneously encoded in the categorical notion of a natural transformation of functors. In…

Quantum Physics · Physics 2026-02-19 Boyu Yang , James Fullwood

We develop elements of a general dilation theory for operator-valued measures and bounded linear maps between operator algebras that are not necessarily completely-bounded. We prove our main results by extending and generalizing some known…

Operator Algebras · Mathematics 2012-07-23 Deguang Han , David R. Larson , Bei Liu , Rui Liu

We present adaptive measurement techniques tailored for variational quantum algorithms on near-term small and noisy devices. In particular, we generalise earlier "learning to measure" strategies in two ways. First, by considering a class of…

Recently foundational issues of applicability of the formalism of quantum mechanics (QM) to cognitive psychology, decision making, and psychophysics attracted a lot of interest. In particular, in \cite{DKBB} the possibility to use of the…

Neurons and Cognition · Quantitative Biology 2014-12-30 Andrei Khrennikov , Irina Basieva

We propose a feasible experimental scheme to direct measure heat and work in cold atomic setups. The method is based on a recent proposal which shows that work is a positive operator valued measure (POVM). In the present contribution, we…

Quantum Gases · Physics 2015-03-25 G. De Chiara , A. J. Roncaglia , J. P. Paz

We generalize Lyapunov's convexity theorem for classical (scalar-valued) measures to quantum (operator-valued) measures. In particular, we show that the range of a nonatomic quantum probability measure is a weak*-closed convex set of…

Functional Analysis · Mathematics 2018-09-12 Sarah Plosker , Christopher Ramsey

The general formalism of quantum mechanics for the description of statistical experiments is briefly reviewed, introducing in particular position and momentum observables as POVM characterized by their covariance properties with respect to…

Quantum Physics · Physics 2009-10-27 Bassano Vacchini

A suitable generalized measurement described by a 4-element positive operator-valued measure (POVM) on each particle of a two-qubit system in the singlet state is, from the point of view of Einstein, Podolsky, and Rosen's (EPR's) criterion…

Quantum Physics · Physics 2009-07-28 Adan Cabello

Measurement is the only part of a general quantum system that has yet to be characterized experimentally in a complete manner. Detector tomography provides a procedure for doing just this; an arbitrary measurement device can be fully…

Spontaneous parametric down conversion (PDC), in the perturbative limit, can be considered as a probabilistic splitting of one input photon into two output photons. Conversely, sum-frequency generation (SFG) implements the reverse process…

Quantum Physics · Physics 2021-04-21 Sofiane Merkouche , Valérian Thiel , Brian J. Smith

We identify an operational principle that singles out Projection-Valued Measures (PVMs) among general Positive Operator-Valued Measures (POVMs), bridging the modern quantum measurement theory and the traditional formulation based on…

Quantum Physics · Physics 2026-05-29 Shun Umekawa , Koki Ono , Hayato Arai

We present graphical representation for genaralized quantum measurements (POVM). We represent POVM elements as Bloch vectors and find the conditions these vectors should satisfy in order to describe realizable physical measurements. We show…

Quantum Physics · Physics 2007-05-23 Pawel Kurzynski , Andrzej Grudka

We consider the convex set of positive operator valued measures (POVM) which are covariant under a finite dimensional unitary projective representation of a group. We derive a general characterization for the extremal points, and provide…

Quantum Physics · Physics 2007-05-23 Giulio Chiribella , Giacomo Mauro D'Ariano

We define a p-norm in the context of quantum random variables, measurable operator-valued functions with respect to a positive operator-valued measure. This norm leads to a operator-valued L^p space that is shown to be complete. Various…

Functional Analysis · Mathematics 2021-08-31 Christopher Ramsey , Adam Reeves

Inspired by some problems in Quantum Information Theory, we present some results concerning decompositions of positive operators acting on finite dimensional Hilbert spaces. We focus on decompositions by families having geometrical symmetry…

Functional Analysis · Mathematics 2017-03-23 Maria Anastasia Jivulescu , Ion Nechita , Pasc Gavruta

We investigate two aspects of the elementary example of POVMs on the Euclidean plane, namely their status as quantum observables and their role as quantizers in the integral quantization procedure. The compatibility of POVMs in the ensuing…

Quantum Physics · Physics 2022-10-19 Roberto Beneduci , Emmanuel Frion , Jean-Pierre Gazeau , Amedeo Perri

It is crucial for various quantum information processing tasks that the state of a quantum system can be determined reliably and efficiently from general quantum measurements. One important class of measurements for this purpose is…

Quantum Physics · Physics 2012-12-17 Gelo Noel M. Tabia

We define a positive operator valued measure $E$ on $[0,2\pi]\times R$ describing the measurement of randomly sampled quadratures in quantum homodyne tomography, and we study its probabilistic properties. Moreover, we give a mathematical…

Mathematical Physics · Physics 2015-05-13 P. Albini , E. De Vito , A. Toigo