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Related papers: Quantum incompatibility in collective measurements

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The fundamental principles of complementarity and uncertainty are shown to be related to the possibility of joint unsharp measurements of pairs of noncommuting quantum observables. A new joint measurement scheme for complementary…

Quantum Physics · Physics 2009-11-07 P. Busch , C. R. Shilladay

A quantum observable and a channel are considered compatible if they form parts of the same measurement device, otherwise they are incompatible. Constrains on compatibility between observables and channels can be quantified via relations…

Quantum Physics · Physics 2018-02-28 T. Heinosaari , D. Reitzner , T. Rybár , M. Ziman

The recently established universal uncertainty principle revealed that two nowhere commuting observables can be measured simultaneously in some state, whereas they have no joint probability distribution in any state. Thus, one measuring…

Quantum Physics · Physics 2011-06-24 Masanao Ozawa

Quantum states and measurements exhibit wave-like --- continuous, or particle-like --- discrete, character. Hybrid discrete-continuous photonic systems are key to investigating fundamental quantum phenomena, generating superpositions of…

We investigate the optimal approximation to triple incompatible quantum measurements within the framework of statistical distance and joint measurability. According to the lower bound of the uncertainty inequality presented in [Physical…

Quantum Physics · Physics 2022-06-01 Hui-Hui Qin , Shao-Ming Fei

Measurements in quantum theory exhibit incompatibility, i.e., they can fail to be jointly measurable. An intuitive way to represent the (in)compatibility relations among a set of measurements is via a hypergraph representing their joint…

Quantum Physics · Physics 2020-11-04 Nikola Andrejic , Ravi Kunjwal

We consider the problem of certifying measurement incompatibility in a prepare-and-measure (PM) scenario. We present different families of sets of qubit measurements which are incompatible, but cannot lead to any quantum over classical…

Quantum Physics · Physics 2025-09-22 Sophie Egelhaaf , Jef Pauwels , Marco Túlio Quintino , Roope Uola

A central result in the foundations of quantum mechanics is the Kochen-Specker theorem. In short, it states that quantum mechanics is in conflict with classical models in which the result of a measurement does not depend on which other…

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

We explore the possibility of achieving optimal joint measurements of noncommuting observables on a single quantum system by performing conventional measurements of commuting self adjoint operators on optimal clones of the original quantum…

Quantum Physics · Physics 2009-11-06 G. M. D'Ariano , C. Macchiavello , M. F. Sacchi

Quantum coherence is a fundamental resource that quantum technologies exploit to achieve performance beyond that of classical devices. A necessary prerequisite to achieve this advantage is the ability of measurement devices to detect…

Based on phase-space structures of quantum states, we propose a novel measure to quantify macroscopic quantum superpositions. Our measure simultaneously quantifies two different kinds of essential information for a given quantum state in a…

Quantum Physics · Physics 2011-06-02 Chang-Woo Lee , Hyunseok Jeong

Measurements in many-body quantum systems can generate non-trivial phenomena, such as preparation of long-range entangled states, dynamical phase transitions, or measurement-altered criticality. Here, we introduce a new measurement scheme…

Quantum Physics · Physics 2025-10-22 Alexey Milekhin , Sara Murciano

Everett's interpretation of quantum mechanics was proposed to avoid problems inherent in the prevailing interpretational frame. It assumes that quantum mechanics can be applied to any system and that the state vector always evolves…

Quantum Physics · Physics 2017-05-03 Louis Marchildon

In this work we establish rigorously a measurement uncertainty relation (MUR) for three unbiased qubit observables, which was previously shown to hold true under some presumptions. The triplet MUR states that the uncertainty, which is…

Quantum Physics · Physics 2022-11-28 Sixia Yu , Ya-Li Mao , Chang Niu , Hu Chen , Zheng-Da Li , Jingyun Fan

We present a review and discussions on characterizations and quantifications of macroscopic quantum states as well as their implementations and applications in optical systems. We compare and criticize different measures proposed to define…

Quantum Physics · Physics 2015-03-24 Hyunseok Jeong , Minsu Kang , Hyukjoon Kwon

An n-qubit quantum register can in principle be completely controlled by operating on a single qubit that interacts with the register via an appropriate fixed interaction. We consider a hypothetical system consisting of n spin-1/2 nuclei…

Quantum Physics · Physics 2009-11-07 Dominik Janzing , Thomas Decker , Thomas Beth

We introduce the notion of compatibility dimension for a set of quantum measurements: it is the largest dimension of a Hilbert space on which the given measurements are compatible. In the Schr\"odinger picture, this notion corresponds to…

Quantum Physics · Physics 2022-10-26 Faedi Loulidi , Ion Nechita

Heisenberg's uncertainty principle is one of the main tenets of quantum theory. Nevertheless, and despite its fundamental importance for our understanding of quantum foundations, there has been some confusion in its interpretation: although…

Quantum Physics · Physics 2013-05-06 Cyril Branciard

In this Letter we investigate the concept of quantum work and its measurability from the viewpoint of quantum measurement theory. Very often, quantum work and fluctuation theorems are discussed in the framework of projective two-point…

Quantum Physics · Physics 2022-08-11 Konstantin Beyer , Roope Uola , Kimmo Luoma , Walter T. Strunz