English
Related papers

Related papers: Nonlocal quantum state ensembles and quantum data …

200 papers

The certification of entanglement in multipartite scenarios is crucial for the advancement of quantum technologies, particularly for the realization of large-scale quantum networks. Here, we introduce a method to certify the structure of…

Quantum Physics · Physics 2026-04-07 Carles Roch I Carceller

Quantum nonlocality is usually associated with entangled states by their violations of Bell-type inequalities. However, even unentangled systems, whose parts may have been prepared separately, can show nonlocal properties. In particular, a…

Quantum Physics · Physics 2019-02-06 Saronath Halder , Manik Banik , Sristy Agrawal , Somshubhro Bandyopadhyay

We present a simple hidden variable model for the singlet state of a pair of qubits, characterized by two kinds, hierarchically ordered, of hidden variables. We prove that, averaging over both types of variables, one reproduces all the…

Quantum Physics · Physics 2015-06-04 GianCarlo Ghirardi , Raffaele Romano

Quantum steering describes the ability of one observer to nonlocally affect the other observer's state through local measurements, which represents a new form of quantum nonlocal correlation and has potential applications in quantum…

Quantum Physics · Physics 2020-10-06 Guo-Zhu Pan , Jun-Long Zhao , Zhi Lin , Ming Yang , Gang Zhang , Zhuo-Liang Cao

The behaviour under particle loss of entanglement and nonlocality is investigated in multipartite quantum systems. In particular, we define a notion of persistency of nonlocality, which leads to device-independent tests of persistent…

Quantum Physics · Physics 2012-10-16 Nicolas Brunner , Tamas Vertesi

Quantum information science has leaped forward with the exploration of high-dimensional quantum systems, offering greater potential than traditional qubits in quantum communication and quantum computing. To advance the field of…

Quantum states can be written in infinitely many ways depending on the choices of basis. Schmidt decomposition of a quantum state has a lot of properties useful in the study of entanglement. All bipartite states admit Schmidt decomposition,…

Quantum Physics · Physics 2026-03-13 Mithilesh Kumar

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

Classical information encoded in composite quantum states can be completely hidden from the reduced subsystems and may be found only in the correlations. Can the same be true for quantum information? If quantum information is hidden from…

Quantum Physics · Physics 2018-06-14 Kavan Modi , Arun Kumar Pati , Aditi Sen De , Ujjwal Sen

Here is considered a specific detection loophole, that is relevant not only to testing of quantum nonlocality, but also to some other applications of quantum computations and communications. It is described by a simple affine relation…

Quantum Physics · Physics 2007-05-23 Alexander Yu. Vlasov

Quantum nonlocality is a kind of significant quantum correlation that is stronger than quantum entanglement and EPR steering. The standard tripartite nonlocality can be detected by the violation of the Mermin inequality. By using local…

Quantum Physics · Physics 2022-05-24 Qiao-Qiao Lv , Jin-Min Liang , Zhi-Xi Wang , Shao-Ming Fei

Quantum correlations are of fundamental importance in quantum phenomena and quantum information processing studies. The measure of quantum correlations is one central issue. The recently proposed measure of quantum correlations, the local…

Quantum Physics · Physics 2015-12-29 Shuhao Wang , Hui Li , Xian Lu , Bin Chen , Gui Lu Long

The celebrated Einstein-Podolsky-Rosen quantum steering has a complex structure in the multipartite scenario. We show that a naively defined criterion for multipartite steering allows, like in Bell nonlocality, for a contradictory effect…

Quantum Physics · Physics 2021-05-07 M. M. Taddei , T. L. Silva , R. V. Nery , G. H. Aguilar , S. P. Walborn , L. Aolita

Bound entanglement is a special form of quantum entanglement that cannot be used for distillation, i.e., the local transformation of copies of arbitrarily entangled states into a smaller number of approximately maximally entangled states.…

Quantum Physics · Physics 2025-08-01 Beatrix C. Hiesmayr , Christopher Popp , Tobias C. Sutter

We study the relations between quantum coherence and quantum nonlocality, genuine quantum entanglement and genuine quantum nonlocality. We show that the coherence of a qubit state can be converted to the nonlocality of two-qubit states via…

Quantum Physics · Physics 2019-09-04 Ya Xi , Tinggui Zhang , Zhujun Zheng , Xianqing Li-Jost , Shao-Ming Fei

The possibility of masking an accelerated two-qubit system by using a minimum number of qubits is discussed. It is shown that, the information may be masked in either entangled local states or product non-local separable states. We examine…

Quantum Physics · Physics 2020-09-11 A. G. Abdelwahab , Nasser Metwally , M. H. Mahran , A-S F Obada

Complex numbers are central to the formulation of quantum mechanics, yet their role as a genuine resource is only beginning to be understood. In this work, we demonstrate that quantum states with intrinsically complex amplitudes provide a…

Quantum Physics · Physics 2026-04-09 Subrata Bera , Indranil Biswas , Atanu Bhunia , Indrani Chattopadhyay , Debasis Sarkar

Random local measurements have recently been proposed to construct entanglement witnesses and thereby detect the presence of bipartite entanglement. We experimentally demonstrate the efficacy of one such scheme on a two-qubit NMR quantum…

Quantum Physics · Physics 2016-12-13 Amandeep Singh , Arvind , Kavita Dorai

Ever since entanglement was identified as a computational and cryptographic resource, effort has been made to find an efficient way to tell whether a given density matrix represents an unentangled, or separable, state. Essentially, this is…

Data Structures and Algorithms · Computer Science 2007-05-23 Lawrence M. Ioannou

The violations of Bell inequalities by measurements on quantum states give rise to the phenomenon of quantum non-locality and express the advantage of using quantum resources over classical ones for certain information-theoretic tasks. The…

Quantum Physics · Physics 2020-11-30 Abderramán Amr , Carlos Palazuelos , Julio I. de Vicente