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Related papers: A Note on Equivalence of Bipartite States under Lo…

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Local unitary invariants allow one to test whether multipartite states are equivalent up to local basis changes. Equivalently, they specify the geometry of the "orbit space" obtained by factoring out local unitary action from the state…

Quantum Physics · Physics 2012-12-27 Graeme Mitchison

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 derive necessary and sufficient conditions for the LU-equivalence of two general (pure or mixed) $n$-qubit states as well as we determine the local unitary operators connecting them. Almost all relevant information is contained in the…

Quantum Physics · Physics 2015-04-15 A. M. Martins

Invertible local transformations of a multipartite system are used to define equivalence classes in the set of entangled states. This classification concerns the entanglement properties of a single copy of the state. Accordingly, we say…

Quantum Physics · Physics 2009-11-06 W. Dür , G. Vidal , J. I. Cirac

We investigate whether pure entangled states can be associated to a measurement basis in which all vectors are local unitary transformations of the original state. We prove that for bipartite states with a local dimension that is either $2,…

Quantum Physics · Physics 2023-08-28 Florian Pimpel , Martin J. Renner , Armin Tavakoli

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

We present a complete set of local unitary invariants for generic multi-qubit systems which gives necessary and sufficient conditions for two states being local unitary equivalent. These invariants are canonical polynomial functions in…

Quantum Physics · Physics 2015-08-06 Naihuan Jing , Shao-Ming Fei , Ming Li , Xianqing Li-Jost , Tinggui Zhang

Given L-qubit states with the fixed spectra of reduced one-qubit density matrices, we find a formula for the minimal number of invariant polynomials needed for solving local unitary (LU) equivalence problem, that is, problem of deciding if…

Quantum Physics · Physics 2014-07-18 Tomasz Maciazek , Michał Oszmaniec , Adam Sawicki

We compute the field of rational local unitary invariants for locally maximally mixed states and symmetrically mixed states of two qubits. In both cases, we prove that the field of rational invariants is purely transcendental. We also…

Algebraic Geometry · Mathematics 2023-08-09 Luca Candelori , Vladimir Y. Chernyak , John R. Klein , Nick Rekuski

We introduce new entanglement monotones which generalize, to the case of many parties, those which give rise to the majorization-based partial ordering of bipartite states' entanglement. We give some examples of restrictions they impose on…

Quantum Physics · Physics 2009-11-07 H. Barnum , N. Linden

Understanding multipartite entanglement is vital, as it underpins a wide range of phenomena across physics. The study of transformations of states via Local Operations assisted by Classical Communication (LOCC) allows one to quantitatively…

Quantum Physics · Physics 2021-09-01 Antoine Neven , David Gunn , Martin Hebenstreit , Barbara Kraus

We give a one-to-one correspondence between classes of density matrices under local unitary invariance and the double cosets of unitary groups. We show that the interrelationship among classes of local unitary equivalent multi-partite mixed…

Quantum Physics · Physics 2020-09-08 Naihuan Jing

We present networks for directly estimating the polynomial invariants of multi-party quantum states under local transformations. The structure of these networks is closely related to the structure of the invariants themselves and this lends…

Quantum Physics · Physics 2009-11-10 M. S. Leifer , N. Linden , A. Winter

We present local invariants of multi-partite pure or mixed states, which can be easily calculated and have a straight-forward physical meaning. As an application, we derive a new entanglement criterion for arbitrary mixed states of $n$…

Quantum Physics · Physics 2007-05-23 Hans Aschauer , John Calsamiglia , Marc Hein , Hans J. Briegel

We study when a multipartite non--local unitary operation can deterministically or probabilistically simulate another one when local operations of a certain kind -in some cases including also classical communication- are allowed. In the…

Quantum Physics · Physics 2007-05-23 W. Dür , J. I. Cirac

We study the problem of transforming a set of pure bipartite states into another using deterministic LOCC (local operations and classical communication). Necessary conditions for the existence of such a transformation are obtained using…

Quantum Physics · Physics 2022-06-27 Somshubhro Bandyopadhyay , Saronath Halder , Ritabrata Sengupta

In this letter we have established the physical character of pure bipartite states with the same amount of entanglement in the same Schmidt rank that either they are local unitarily connected or they are incomparable. There exist infinite…

Quantum Physics · Physics 2008-05-20 Indrani Chattopadhyay , Debasis Sarkar

Motivated by link transformations of lattice gauge theory, a method for generating local unitary invariants, especially for a system of qubits, has been pointed out in an earlier work [M. S. Williamson {\it et. al.}, Phys. Rev. A {\bf 83},…

Quantum Physics · Physics 2013-05-16 Udaysinh T. Bhosale , K. V. Shuddhodan , Arul Lakshminarayan

For a tripartite pure state superposed by two individual states, the bipartitely shared entanglement can always be achieved by local measurements of the third party. Consider the different aims of the third party, i.e. maximizing or…

Quantum Physics · Physics 2009-11-13 Chang-shui Yu , X. X. Yi , He-shan Song

In this paper, we consider the local unitary classification of the class of qudit bipartite mixed states for which no information can be obtained locally. These states are represented by symmetrical density matrices in which both tracial…

Quantum Physics · Physics 2023-04-25 Constantino Rodriguez-Ramos , Colin M. Wilmott