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Related papers: Maximally incompatible quantum observables

200 papers

We show that number and canonical phase (of a single mode optical field) are complementary observables. We also bound the measurement uncertainty region for their approximate joint measurements.

Quantum Physics · Physics 2018-02-05 Pekka Lahti , Juha-Pekka Pellonpää , Jussi Schultz

The notion of incompressible momentum observables is introduced. It is shown that when the metric in a manifold has a certain form, a set of canonically conjugate variables Xk and Pk in which Pk are incompressible, can be constructed. Based…

Mathematical Physics · Physics 2007-05-23 C. P. Viazminsky

We study various optimality criteria for quantum observables. Observables are represented as covariant positive operator valued measures and we consider the case when the symmetry group is compact. Phase observables are examined as an…

Quantum Physics · Physics 2009-04-08 Claudio Carmeli , Teiko Heinosaari , Juha-Pekka Pellonpää , Alessandro Toigo

Maximal sets of mutually unbiased bases are useful throughout quantum physics, both in a foundational context and for applications. To date, it remains unknown if complete sets of mutually unbiased bases exist in Hilbert spaces of…

Quantum Physics · Physics 2026-04-09 Daniel McNulty , Stefan Weigert

We investigate the optimal distribution of quantum information over multipartite systems in asymmetric settings. We introduce cloning transformations that take $N$ identical replicas of a pure state in any dimension as input, and yield a…

Quantum Physics · Physics 2009-11-10 S. Iblisdir , A. Acin , N. Gisin , J. Fiurasek , R. Filip , N. J. Cerf

The concept of entanglement and separability of quantum states is relevant for several fields in physics. Still, there is a lack of effective operational methods to characterise these features. We propose a method to certify quantum…

Quantum Physics · Physics 2024-03-06 Ties-A. Ohst , Xiao-Dong Yu , Otfried Gühne , H. Chau Nguyen

We consider the separability of various joint states of D-dimensional quantum systems, which we call "qudits." We derive two main results: (i) the separability condition for a two-qudit state that is a mixture of the maximally mixed state…

Quantum Physics · Physics 2012-01-04 P. Rungta , W. J. Munro , K. Nemoto , P. Deuar , G. J. Milburn , C. M. Caves

We show that, contrarily to the widespread belief, in quantum mechanics repeatable measurements are not necessarily described by orthogonal projectors--the customary paradigm of "observable". Nonorthogonal repeatability, however, occurs…

Quantum Physics · Physics 2007-05-23 F. Buscemi , G. M. D'Ariano , P. Perinotti

Here, asymmetric phase-covariant quantum cloning machines are defined and trade-off between qualities of their outputs and its impact on entanglement properties of the outputs are studies. In addition, optimal families among these cloners…

Quantum Physics · Physics 2008-04-23 A. T. Rezakhani , S. Siadatnejad , A. H. Ghaderi

A transformation achieving the optimal symmetric N-to-M cloning of coherent states is presented. Its implementation only requires a phase-insensitive linear amplifier and a network of beam splitters. An experimental demonstration of this…

Quantum Physics · Physics 2009-11-06 Samuel L. Braunstein , Nicolas J. Cerf , Sofyan Iblisdir , Peter van Loock , Serge Massar

Quantum measurements are not deterministic. For this reason quantum measurements are repeated for a number of shots on identically prepared systems. The uncertainty in each measurement depends on the number of shots and the expected outcome…

Quantum Physics · Physics 2025-03-12 Pieter Thijs Eendebak

We study two operational approaches to quantifying incompatibility that depart significantly from the well known entropic uncertainty relation (EUR) formalism. Both approaches result in incompatibility measures that yield non-zero values…

Quantum Physics · Physics 2015-10-15 Srijita Kundu , Kaustubh Wagh , Prabha Mandayam

In quantum theory, there exist sets of operations that cannot be performed simultaneously. These sets of operations are referred to as incompatible. While this definition of incompatibility extends to general probabilistic theories (GPTs),…

Quantum Physics · Physics 2024-12-12 Masataka Yamada , Takayuki Miyadera

We study different notions of quantum correlations in multipartite systems of distinguishable and indistinguishable particles. Based on the definition of quantum coherence for a single particle, we consider two possible extensions of this…

Quantum Physics · Physics 2017-09-27 Jan Sperling , Armando Perez-Leija , Kurt Busch , Ian A. Walmsley

While exact cloning of an unknown quantum state is prohibited by the linearity of quantum mechanics, approximate cloning is possible and has been used, e.g., to derive limits on the security of quantum communication protocols. In the case…

Quantum Physics · Physics 2009-11-13 Hongwei Chen , Xianyi Zhou , Dieter Suter , Jiangfeng Du

We investigate correlations among complementary observables. In particular, we show how to take advantage of mutually unbiased bases (MUBs) for the efficient detection of entanglement in arbitrarily high-dimensional, multipartite and…

Symmetric informationally complete measurements are both important building blocks in many quantum information protocols and the seminal example of a generalised, non-orthogonal, quantum measurement. In higher-dimensional systems, these…

The uncertainty relation lies at the heart of quantum theory and behaves as a non-classical constraint on the indeterminacies of incompatible observables in a system. In the literature, many experiments have been devoted to the test of the…

Quantum Physics · Physics 2022-04-20 Shuang Wang , Fang-Xia Meng , Hui Wang , Cong-Feng Qiao

Distinguishing quantum states that admit a classical counterpart from those that exhibit nonclassicality has long been a central issue in quantum optics. Finding an implementable criterion certifying optical nonclassicality (i.e, the…

Quantum Physics · Physics 2022-10-13 Matthieu Arnhem , Célia Griffet , Nicolas J. Cerf

We show a general approach for detecting genuine multipartite entanglement (GME) and partial inseparability in many-body-systems by means of macroscopic observables (such as the energy) only. We show that the obtained criteria, the "GME…

Quantum Physics · Physics 2013-03-04 Andreas Gabriel , Beatrix C. Hiesmayr