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Related papers: On Quantum Operations as Quantum States

200 papers

Determining the relationship between composite systems and their subsystems is a fundamental problem in quantum physics. In this paper we consider the spectra of a bipartite quantum state and its two marginal states. To each spectrum we can…

Quantum Physics · Physics 2007-05-23 Matthias Christandl , Graeme Mitchison

We present a general formalism with the aim of describing the situation of an entity, how it is, how it reacts to experiments, how we can make statistics with it, and how it changes under the influence of the rest of the universe. Therefore…

Quantum Physics · Physics 2007-05-23 Diederik Aerts

The partial trace operation is usually considered in composite quantum systems, to reduce the state on a single subsystem. This operation has a key role in the decoherence effect and quantum measurements. However, partial trace operations…

Quantum Physics · Physics 2024-03-18 Quentin Ansel

The consistent histories formulation of the quantum theory of a closed system with pure initial state defines an infinite number of incompatible consistent sets, each of which gives a possible description of the physics. We investigate the…

General Relativity and Quantum Cosmology · Physics 2011-08-04 Adrian Kent , Jim McElwaine

The completeness of quantum state space, is usually expressed as \sum_{m=0}^{\infty}|m><m|=1, where {|m>} is selected set of quantum states (basis). Density matrix |m><m| describes a pure quantum state. In this paper, by virtue of the…

Quantum Physics · Physics 2017-11-28 Hongyi Fan , Jun-hua Chen , Dehui Zhan , Liyun Hu

The relation between completely positive maps and compound states is investigated in terms of the notion of quantum conditional probability.

Quantum Physics · Physics 2007-05-23 M. Asorey , A. Kossakowski , G. Marmo , E. C. G. Sudarshan

Quasiprobability representations are well-established tools in quantum information science, with applications ranging from the classical simulability of quantum computation to quantum process tomography, quantum error correction, and…

We show how the separability problem is dual to that of decomposing any given matrix into a conic combination of rank-one partial isometries, thus offering a duality approach different to the positive maps characterization problem. Several…

Quantum Physics · Physics 2007-05-23 D. Salgado , J. L. Sanchez-Gomez , M. Ferrero

We introduce a general method for the construction of quasiprobability representations for arbitrary notions of quantum coherence. Our technique yields a nonnegative probability distribution for the decomposition of any classical state.…

Quantum Physics · Physics 2018-06-22 J. Sperling , I. A. Walmsley

Quantum coherence is an essential feature of quantum mechanics which is responsible for the departure between classical and quantum world. The recently established resource theory of quantum coherence studies possible quantum technological…

Quantum Physics · Physics 2017-10-06 Alexander Streltsov , Swapan Rana , Paul Boes , Jens Eisert

Starting from a new principle inspired by quantum tomography rather than from Born's rule, this paper gives a self-contained deductive approach to quantum mechanics and quantum measurement. A suggestive notion for what constitutes a quantum…

Quantum Physics · Physics 2024-05-22 Arnold Neumaier

The purpose of this paper is to introduce several basic theorems of coherent states and generalized coherent states based on Lie algebras su(2) and su(1,1), and to give some applications of them to quantum information theory for graduate…

Quantum Physics · Physics 2007-05-23 Kazuyuki Fujii

The main purpose of thispaper is to show that composite quantum-like (QL) systems can closely mimic the separable states of quantum systems, and that suitable physical systems exhibiting these states exist. It is shown that QL graphs can…

Quantum Physics · Physics 2026-03-24 Gregory D. Scholes

The scientific methodology based on two descriptive levels, ontic (reality as it is ) and epistemic (observational), is briefly presented. Following Schr\"odinger, we point to the possible gap between these two descriptions. Our main aim is…

Quantum Physics · Physics 2018-08-07 Andrei Khrennikov

Given a finite group G with a bilocal representation, we investigate the bipartite entanglement in the state constructed from the group algebra of G acting on a separable reference state. We find an upper bound for the von Neumann entropy…

Quantum Physics · Physics 2007-05-23 Alioscia Hamma , Radu Ionicioiu , Paolo Zanardi

Electron transport in realistic physical and chemical systems often involves the non-trivial exchange of energy with a large environment, requiring the definition and treatment of open quantum systems. Because the time evolution of an open…

Many fundamental and key objects in quantum mechanics are linear mappings between particular affine/linear spaces. This structure includes basic quantum elements such as states, measurements, channels, instruments, non-signalling channels…

Quantum Physics · Physics 2024-07-19 Simon Milz , Marco Túlio Quintino

We show that quantum operations on multi-particle systems have a non-local content; this mirrors the non-local content of quantum states. We introduce a general framework for discussing the non-local content of quantum operations, and give…

Quantum Physics · Physics 2023-03-27 Daniel Collins , Noah Linden , Sandu Popescu

We present a generalization of quantum Stein's Lemma to the situation in which the alternative hypothesis is formed by a family of states, which can moreover be non-i.i.d.. We consider sets of states which satisfy a few natural properties,…

Quantum Physics · Physics 2010-03-10 Fernando G. S. L. Brandao , Martin B. Plenio

For two symmetric quantum states one may be interested in maximizing the overlap under local operations applied to one of them. The question arises whether the maximal overlap can be obtained by applying the same local operation to each…

Quantum Physics · Physics 2017-02-15 Antoine Neven , Pierre Mathonet , Otfried Gühne , Thierry Bastin