English
Related papers

Related papers: All Entangled Quantum States Are Nonlocal

200 papers

Quantum steering, loosely speaking the distribution of entanglement from an untrusted party, is a form of quantum nonlocality which is intermediate between entanglement and Bell nonlocality. Determining which states can be steered is…

Quantum Physics · Physics 2013-03-06 Nicolas Brunner , Daniel Cavalcanti

Quantum nonlocality is arguably among the most counter-intuitive phenomena predicted by quantum theory. In recent years, the development of an abstract theory of nonlocality has brought a much deeper understanding of the subject. In…

We study the local indistinguishability problem of quantum states. By introducing an easily calculated quantity, non-commutativity, we present an criterion which is both necessary and sufficient for the local indistinguishability of a…

Quantum Physics · Physics 2014-09-17 Teng Ma , Ming-Jing Zhao , Yao-Kun Wang , Shao-Ming Fei

The problem of quantum state discrimination, which is a foundational aspect of quantum information theory, and its relation to the theory of majorization are discussed. The purpose of this study is to review different approaches to the…

Quantum Physics · Physics 2016-02-22 Ozenc Gungor

The notion of entanglement of quantum states is usually defined with respect to a fixed bipartition. Indeed, a global basis change can always map an entangled state to a separable one. The situation is however different when considering a…

Quantum Physics · Physics 2021-06-02 Yu Cai , Baichu Yu , Pooja Jayachandran , Nicolas Brunner , Valerio Scarani , Jean-Daniel Bancal

While all bipartite pure entangled states are known to generate correlations violating a Bell inequality, and are therefore nonlocal, the quantitative relation between pure-state entanglement and nonlocality is poorly understood. In fact,…

Quantum Physics · Physics 2018-08-14 Victoria Lipinska , Florian Curchod , Alejandro Máttar , Antonio Acín

Recently developed quantum algorithms suggest that quantum computers can solve certain problems and perform certain tasks more efficiently than conventional computers. Among other reasons, this is due to the possibility of creating…

Quantum Physics · Physics 2007-05-23 Rolando D. Somma

We show that there is a stronger form of bipartite quantum nonlocality in which systems that never interacted are as nonlocal as allowed by no-signaling. For this purpose, we first show that nonlocal boxes, theoretical objects that violate…

Quantum Physics · Physics 2012-11-26 Adan Cabello

Entangled physical systems are an important resource in quantum information. Some authors claim that in fact all quantum states are entangled. In this paper we show that this claim is incorrect and we discuss in operational way differences…

Quantum Physics · Physics 2016-10-07 Marian Kupczynski

We consider the transformation of multisystem entangled states by local quantum operations and classical communication. We show that, for any reversible transformation, the relative entropy of entanglement for two parties must remain…

Quantum Physics · Physics 2007-05-23 N. Linden , S. Popescu , B. Schumacher , M. Westmoreland

When dealing with macroscopic objects one usually observes quasiclassical phenomena, which can be described in terms of quasiclassical (or classical) equations of motion. Recent development of the theory of quantum computation is based on…

Quantum Physics · Physics 2007-05-23 Gennady P. Berman , Gary D. Doolen , Gustavo V. Lopez , Vladimir I. Tsifrinovich

Locally real states of electromagnetic radiation derived from the underlying quantum mechanical formalism are shown to provide an alternative basis for definite polarized states of the widely accepted probabilistic interpretation. The…

General Physics · Physics 2023-07-07 Stuart Mirell , Daniel Mirell

Suppose that two distant parties Alice and Bob share an entangled state $\rho_{AB}$, and they want to exchange the subsystems of $\rho_{AB}$ by local operations and classical communication (LOCC). In general, this LOCC task (i.e. the LOCC…

Quantum Physics · Physics 2015-09-30 Takaya Ikuto , Satoshi Ishizaka

We analyze approximate transformations of pure entangled quantum states by local operations and classical communication, finding explicit conversion strategies which optimize the fidelity of transformation. These results allow us to…

Quantum Physics · Physics 2009-10-31 Guifre Vidal , Daniel Jonathan , M. A. Nielsen

It is nowadays accepted that truly quantum correlations can exist even in the absence of entanglement. For the case of symmetric states, a physically trivial unitary transformation can alter a quantum state from entangled to separable and…

Quantum Physics · Physics 2022-02-24 Aaron Z. Goldberg , Markus Grassl , Gerd Leuchs , Luis L. Sánchez-Soto

Understanding what can be inferred about a multi-particle quantum system from only the knowledge of its subparts is a highly non-trivial task. Clearly, if the global system doesn't contain any information resource, nor do its subparts.…

Quantum Physics · Physics 2013-05-30 Lars Erik Würflinger , Jean-Daniel Bancal , Antonio Acín , Nicolas Gisin , Tamas Vertesi

The quantum mechanics formalism introduced new revolutionary concepts challenging our everyday perceptions. Arguably, quantum entanglement, which explains correlations that cannot be reproduced classically, is the most notable of them.…

Entanglement is a fundamental resource for many applications in quantum information processing. Here, we investigate how quantum transport in simple quantum graphs, modeled as controlled two-level quantum systems, can be utilized to…

Quantum Physics · Physics 2025-10-24 Alison A. Silva , D. Bazeia , Fabiano M. Andrade

Nonlocality and quantum entanglement constitute two special features of quantum systems of paramount importance in quantum information theory (QIT). Essentially regarded as identical or equivalent for many years, they constitute different…

Quantum Physics · Physics 2016-11-25 J. Batle , M. Casas

According to usual definitions, entangled states cannot be given a separable decomposition in terms of products of local density operators. If we relax the requirement that the local density operators be positive, then an entangled quantum…

Quantum Physics · Physics 2015-10-28 Hussain Anwar , Sania Jevtic , Oliver Rudolph , Shashank Virmani