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Related papers: Nonlocal Properties and Local Invariants for Bipar…

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It was recently shown that the nonseparable density operators for a bipartite system are trace norm dense if either factor space has infinite dimension. We show here that non-local states -- i.e., states whose correlations cannot be…

Quantum Physics · Physics 2009-10-31 Rob Clifton , Hans Halvorson , Adrian Kent

The statistics of local measurements of joint quantum systems can sometimes be used to distinguish the spatiotemporal structure in which they were measured. We first prove that every bipartite separable density matrix is temporally…

Quantum Physics · Physics 2026-01-05 Minjeong Song , Arthur J. Parzygnat

As far as entanglement is concerned, two density matrices of $n$ particles are equivalent if they are on the same orbit of the group of local unitary transformations, $U(d_1)\times...\times U(d_n)$ (where the Hilbert space of particle $r$…

Quantum Physics · Physics 2008-11-26 N. Linden , S. Popescu , A. Sudbery

We address unitary local (UL) invariance of bipartite pure states. Given a bipartite state $|\Psi>>=\sum_{ij} \psi_{ij}\: |i>_1\otimes |j>_2$ the complete characterization of the class of local unitaries $U_1\otimes U_2$ for which…

Quantum Physics · Physics 2007-05-23 Matteo G A Paris

We derive a set of invariants under local unitary transformations for arbitrary dimensional quantum systems. These invariants are given by hyperdeterminants and independent from the detailed pure state decompositions of a given quantum…

Quantum Physics · Physics 2013-09-17 Ting-Gui Zhang , Naihuan Jing , Xianqing Li-Jost , Ming-Jing Zhao , Shao-Ming Fei

We investigate the equivalence of quantum mixed states under local unitary transformations. For a class of rank-two mixed states, a sufficient and necessary condition of local equivalence is obtained by giving a complete set of invariants…

Quantum Physics · Physics 2007-11-09 Sergio Albeverio , Shao-Ming Fei , Debashish Goswami

The equivalence of arbitrary dimensional bipartite states under local unitary transformations (LUT) is studied. A set of invariants and ancillary invariants under LUT is presented. We show that two states are equivalent under LUT if and…

Quantum Physics · Physics 2009-11-13 Bao-Zhi Sun , Shao-Ming Fei , Xianqing Li-Jost , Zhi-Xi Wang

We study the power of local test for bipartite quantum states. Our central result is that, for properties of bipartite pure states, unitary invariance on one part implies an optimal (over all global testers) local tester acting only on the…

Quantum Physics · Physics 2025-06-02 Kean Chen , Qisheng Wang , Zhicheng Zhang

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

Bipartite correlations generated by non-signalling physical systems that admit a finite-dimensional local quantum description cannot exceed the quantum limits, i.e., they can always be interpreted as distant measurements of a bipartite…

Quantum Physics · Physics 2015-06-05 Tom Cooney , Marius Junge , Miguel Navascues , David Perez-Garcia , Ignacio Villanueva

Some quantum information processing protocols necessitate quantum operations that are invariant under complex conjugation. In this study, we analyze the non-local resources necessary for implementing conjugation-symmetric measurements on…

Quantum Physics · Physics 2024-05-31 Jisho Miyazaki , Seiseki Akibue

We propose a natural generalization of bipartite Werner and isotropic states to multipartite systems consisting of an arbitrary even number of d-dimensional subsystems (qudits). These generalized states are invariant under the action of…

Quantum Physics · Physics 2009-11-13 Dariusz Chruscinski , Andrzej Kossakowski

We perform numerical tests on quantum nonlocality of two-level quantum systems (qubits) observed by a uniformly moving observer. Under a suitable momentum setting, the quantum nonlocality of two-qubit nonmaximally entangled states could be…

Quantum Physics · Physics 2015-06-15 Hong-Yi Su , Yu-Chun Wu , Jing-Ling Chen , Chunfeng Wu , L. C. Kwek

Research on quantum states often focuses on the correlation between nonlocal effects and local unitary invariants, among which local unitary equivalence plays a significant role in quantum state classification and resource theories. This…

Quantum Physics · Physics 2025-11-17 Lin Zhang , Bing Xie , Yuanhong Tao

It is argued that the formal rules of correspondence between local observation procedures and observables do not exhaust the entire physical content of generally covariant quantum field theory. This result is obtained by expressing the…

High Energy Physics - Theory · Physics 2009-10-31 Hadi Salehi

We present that the local unitary equivalence of n-party pure states is consistent with the one of their (n-1)-party reduced density matrices. As an application, we obtain the local invariants for a class of tripartite pure qudits.

Quantum Physics · Physics 2011-02-01 Zhen Wang , He-Ping Wang , Zhi-Xi Wang , Shao-Ming Fei

We show that the quantum discord and the measurement induced non-locality (MiN) in a bipartite quantum state is invariant under the action of a local quantum channel if and only if the channel is invertible. In particular, these quantities…

Quantum Physics · Physics 2013-03-06 Ali Saif M. Hassan , Pramod S. Joag

We extend to any maximally entangled state of a bipartite system whose constituents are arbitrarily (but finite) dimensional the result, recently derived for two-dimensional constituents, that hidden variable theories cannot have local…

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

In this letter, a nonlocal effect for a bipartite system which is induced by a local cyclic evolution of one of its subsystem is suggested. This effect vanishes when the system is at a disentangled pure state but can be observed for some…

Quantum Physics · Physics 2009-11-10 Li-Bin Fu

We study the nonlocality of arbitrary dimensional bipartite quantum states. By computing the maximal violation of a set of multi-setting Bell inequalities, an analytical and computable lower bound has been derived for general two-qubit…

Quantum Physics · Physics 2015-09-04 Ming Li , Tinggui Zhang , Bobo Hua , Shao-Ming Fei , Xianqing Li-Jost