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Related papers: On steering in the C*-algebraic framework

200 papers

Quantum steering is considered as one of the most well-known nonlocal phenomena in quantum mechanics. Unlike entanglement and Bell non-locality, the asymmetry of quantum steering makes it vital for one-sided device-independent quantum…

Quantum Physics · Physics 2024-07-11 Li-Juan Li , Xiao-Gang Fan , Xue-Ke Song , Liu Ye , Dong Wang

We define and fully characterize the witnesses based on second moments detecting steering in Gaussian states by means of Gaussian measurements. All such tests, which arise from linear combination of variances or second moments of canonical…

Quantum Physics · Physics 2023-04-25 Tatiana Mihaescu , Hermann Kampermann , Aurelian Isar , Dagmar Bruß

A sequential steering scenario is investigated, where multiple Bobs aim at demonstrating steering using successively the same half of an entangled quantum state. With isotropic entangled states of local dimension $d$, the number of Bobs…

Non-local correlations between a fully characterised quantum system and an untrusted black box device are described by an assemblage of conditional quantum states. These assemblages form a convex set, whose extremal points are relevant in…

Quantum Physics · Physics 2022-09-14 Thomas Cope , Tobias J. Osborne

By combining two objects with no quantum effect one can get an object with quantum effect. Such a phenomenon, often referred to as activation has been analyzed for the notion of steering nonlocality. Activation of steering nonlocality is…

Quantum Physics · Physics 2023-03-22 Kaushiki Mukherjee , Biswajit Paul , Soma Mandal

Quantum correlation is a fundamental property which distinguishes quantum systems from classical ones, and it is also a fragile resource under projective measurement. Recently, it has been shown that a subsystem in entangled pairs can share…

Quantum Physics · Physics 2021-02-25 Kun Liu , Tongjun Liu , Wei Fang , Jian Li , Qin Wang

We generalize the notion of joint measurability to continuous variable systems by extending a recently introduced compression algorithm of quantum measurements to this realm. The extension results in a property that asks for the minimal…

Quantum Physics · Physics 2026-03-03 Pauli Jokinen , Sophie Egelhaaf , Juha-Pekka Pellonpää , Roope Uola

Given two unital C*-algebras equipped with states and a positive operator in the enveloping von Neumann algebra of their minimal tensor product, we define three parameters that measure the capacity of the operator to align with a coupling…

Operator Algebras · Mathematics 2023-08-01 Adam Skalski , Ivan G. Todorov , Lyudmila Turowska

It is shown how a C*-algebra representation of the transformations of a physical system can be derived from two operational postulates: 1) the existence of dynamically independent systems}; 2) the existence of symmetric faithful states.…

Quantum Physics · Physics 2007-10-09 Giacomo Mauro D'Ariano

Quantum steering, as a manifestation of nonlocal quantum correlations, plays a crucial role in enabling various quantum information processing tasks. However, practical implementations are often hindered by significant challenges arising…

Quantum Physics · Physics 2026-04-09 Yan Zhao , Li-Juan Li , Zheng-Peng Xu , Liu Ye , Dong Wang

Quantum steering is a fundamental quantum correlation that plays a pivotal role in quantum technologies, but its verification crucially relies on precise measurements -- an assumption often undermined by practical imperfections. Here, we…

Quantum Physics · Physics 2025-11-12 Zeyang Lu , Chan Li , Gang Wang , Zhu Cao

Einstein-Podolsky-Rosen (EPR) steering is often (implicitly or explicitly) taken to be evidence for spooky action-at-a-distance. An alternative perspective on steering is that Alice has no causal influence on the physical state of Bob's…

Quantum Physics · Physics 2023-02-22 Beata Zjawin , David Schmid , Matty J. Hoban , Ana Belén Sainz

Quantum steering is the central resource for one-sided device-independent quantum information. It is manipulated via one-way local operations and classical communication, such as local filtering on the trusted party. Here, we provide a…

Quantum Physics · Physics 2022-08-26 Huan-Yu Ku , Chung-Yun Hsieh , Shin-Liang Chen , Yueh-Nan Chen , Costantino Budroni

In the Einstein--Podolsky--Rosen experiment, when Alice makes a measurement on her part of a bipartite system, Bob's part is collapsed to, or steered to, a specific ensemble. Moreover, by reading her measurement outcome, Alice can specify…

Quantum Physics · Physics 2017-04-17 H. Chau Nguyen , Kimmo Luoma

Characterising non-classical quantum phenomena is crucial not only from a fundamental perspective, but also to better understand its capabilities for information processing and communication tasks. In this work, we focus on exploring the…

Quantum Physics · Physics 2022-12-16 Vinicius P. Rossi , Matty J. Hoban , Ana Belén Sainz

Tsirelson's problem asks whether the commuting operator model for two-party quantum correlations is equivalent to the tensor-product model. We give a negative answer to this question by showing that there are non-local games which have…

Quantum Physics · Physics 2020-09-29 William Slofstra

Quantumness for a bipartite unsteerable quantum correlation is operationally characterized by the notion of super-unsteerability. Super-unsteerability refers to the requirement of a larger dimension of the random variable that the steering…

In the present work, we address the question of how bipartite steering violation takes place among multi-partite systems (where each sub-system have Hilbert space dimension restricted to two) based on the maximal violations of the bipartite…

There are possible physical theories that give greater violations of Bell's inequalities than the corresponding Tsirelson bound, termed post-quantum non-locality. Such theories do not violate special relativity, but could give an advantage…

Quantum Physics · Physics 2026-01-08 Ana Belén Sainz , Paul Skrzypczyk , Matty J. Hoban

For distinguishing quantum states sampled from a fixed ensemble, the gap in bipartite and single-party distinguishability can be interpreted as a nonlocality of the ensemble. In this paper, we consider bipartite state discrimination in a…

Quantum Physics · Physics 2018-09-18 Seiseki Akibue , Go Kato