English
Related papers

Related papers: Perfect Quantum Privacy Implies Nonlocality

200 papers

Recently the explicit applicability of bound entanglement in quantum cryptography has been shown. In this paper some of recent results respecting this topic are reviewed. In particular relevant notions and definitions are reminded. The new…

Quantum Physics · Physics 2007-12-27 Pawel Horodecki , Remigiusz Augusiak

Authentication is a well-studied area of classical cryptography: a sender S and a receiver R sharing a classical private key want to exchange a classical message with the guarantee that the message has not been modified by any third party…

Quantum Physics · Physics 2016-11-18 Howard Barnum , Claude Crepeau , Daniel Gottesman , Adam Smith , Alain Tapp

Quantum correlation includes quantum entanglement and quantum discord. Both entanglement and discord have a common necessary condition--------quantum coherence or quantum superposition. In this paper, we attempt to give an alternative…

Quantum Physics · Physics 2014-09-23 Chang-shui Yu , Yang Zhang , Haiqing Zhao

We present a Bell-type inequality for four-qubit systems. Using the inequality we investigate quantum nonlocality of a generic family of states $\left|G_{abcd}\right >$ [Phys. Rev. A 65, 052112 (2002)] and several canonical four-qubit…

Quantum Physics · Physics 2017-06-07 Dong Ding , Fengli Yan , Ting Gao

It is argued that while quantum mechanics contains nonlocal or entangled states, the instantaneous or nonlocal influences sometimes thought to be present due to violations of Bell inequalities in fact arise from mistaken attempts to apply…

Quantum Physics · Physics 2012-02-22 Robert B. Griffiths

The observation of quantum nonlocality, i.e. quantum correlations violating a Bell inequality, implies the use of incompatible local quantum measurements. Here we consider the converse question. That is, can any set of incompatible…

Quantum Physics · Physics 2016-06-06 Marco Túlio Quintino , Joseph Bowles , Flavien Hirsch , Nicolas Brunner

We argue that the conclusion of Bell theorem, namely, that there must be spatial non-local correlations in certain experimental situations, does not apply to typical individual measurements performed on entangled EPR pairs. Our claim is…

General Physics · Physics 2015-10-22 Victor Romero-Rochin

Bell inequalities and nonlocality have been widely studied in one-dimensional quantum systems. As a kind of quantum correlation, it is expected that bipartite nonlocaity should be present in quantum systems, just as bipartite entanglement…

Quantum Physics · Physics 2015-06-16 Zhao-Yu Sun , Yu-Ying Wu , Hai-Lin Huang , Bo-Jun Chen , Bo Wang

It is stated by C. Simon, quant-ph/0410032, that the definition of "classicality" used in quant-ph/0310116 is "much narrower than Bell's concept of local hidden variables" and that, in the separable quantum case, the validity of the perfect…

Quantum Physics · Physics 2007-05-23 Elena R. Loubenets

Quantum entanglement plays a central role in many areas of physics, from quantum information science to many-body systems. In order to grasp the essence of this phenomenon, it is fundamental to understand how different manifestations of…

Quantum Physics · Physics 2014-11-11 Tamas Vértesi , Nicolas Brunner

Bell nonlocality -- the existence of quantum correlations that cannot be explained by classical means -- is certainly one of the most striking features of quantum mechanics. Its range of applications in device-independent protocols is…

Quantum Physics · Physics 2023-12-06 Rafael Santos , Debashis Saha , Flavio Baccari , Remigiusz Augusiak

Bell inequality is a mathematical inequality derived using the assumptions of locality and realism. Its violation guarantees the existence of quantum correlations in a quantum state. Bell inequality acts as an entanglement witness in the…

Quantum Physics · Physics 2016-07-29 Kaifeng Bu , Asutosh Kumar , Junde Wu

In this work, we investigate what kinds of quantum states are feasible to perform perfectly secure secret sharing, and present its necessary and sufficient conditions. We also show that the states are bipartite distillable for all bipartite…

Quantum Physics · Physics 2009-11-13 Dong Pyo Chi , Jeong Woon Choi , Jeong San Kim , Taewan Kim , Soojoon Lee

Understanding the relation between nonlocality and entanglement is one of the fundamental problems in quantum physics. In the bipartite case, it is known that the correlations observed for some entangled quantum states can be explained…

Quantum Physics · Physics 2015-07-22 R. Augusiak , M. Demianowicz , J. Tura , A. Acín

It is known that "quantum non locality", leading to the violation of Bell's inequality and more generally of classical local realism, can be attributed to the conjunction of two properties, that we call here elementary locality and…

Quantum Physics · Physics 2022-01-04 Philippe Grangier

This note is a reply to M. Navascu\'es' claim that "all entangled states violate Leggett's crypto-nonlocality" [arXiv:1303.5124v2]. I argue that such a conclusion can only be reached if one introduces additional assumptions that further…

Quantum Physics · Physics 2013-10-21 Cyril Branciard

Whether the quantum mechanics (QM) is non-local is an issue disputed for a long time. The violation of the Bell-type inequalities was considered as proving this non-locality. However, these inequalities are constructed on a class of local…

General Physics · Physics 2015-11-20 Sofia Wechsler

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

The quantum entanglement as one of very important resources has been widely used in quantum information processing. In this work, we present a new kind of genuine multipartite entanglement. It is derived from special geometric feature of…

Quantum Physics · Physics 2021-11-29 Ming-Xing Luo

A novel definition for data privacy in quantum computing based on quantum hypothesis testing is presented in this paper. The parameters in this privacy notion possess an operational interpretation based on the success/failure of an…

Quantum Physics · Physics 2023-02-27 Farhad Farokhi