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Related papers: The exact convex roof for GHZ-W mixtures for three…

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We extend the concept of the negativity, a good measure of entanglement for bipartite pure states, to mixed states by means of the convex-roof extension. We show that the measure does not increase under local quantum operations and…

Quantum Physics · Physics 2009-11-10 Soojoon Lee , Dong Pyo Chi , Sung Dahm Oh , Jaewan Kim

We consider two properties of the set of quantum states as a convex topological space and some their implications concerning the notions of a convex hull and of a convex roof of a function defined on a subset of quantum states. By using…

Mathematical Physics · Physics 2015-05-13 M. E. Shirokov

We establish a general operational one-to-one mapping between coherence measures and entanglement measures: Any entanglement measure of bipartite pure states is the minimum of a suitable coherence measure over product bases. Any coherence…

Quantum Physics · Physics 2017-09-20 Huangjun Zhu , Zhihao Ma , Zhu Cao , Shao-Ming Fei , Vlatko Vedral

We present two ready-to-use numerical algorithms to evaluate convex-roof extensions of arbitrary pure-state entanglement monotones. Their implementation leaves the user merely with the task of calculating derivatives of the respective…

Quantum Physics · Physics 2009-12-08 Beat Röthlisberger , Jörg Lehmann , Daniel Loss

We extend Bloch Sphere formalism to pure two qubit systems. Combining insights from Geometric Algebra and analysis of entanglement in different conjugate bases we identify Two Bloch Sphere geometry that is suitable for representing…

Quantum Physics · Physics 2024-03-19 Stanislav Filatov , Marcis Auzinsh

In this paper, we develop a rigorous mathematical framework for the optimization of hip roof house geometry, with the primary goal of minimizing the external surface of the building envelope for a given set of design constraints. Five…

Optimization and Control · Mathematics 2026-01-21 Ewa Rokita-Magdziarz , Barbara Gronostajska , Marcin Magdziarz

We study the tripartite entanglement for a class of mixed states defined by the mixture of GHZ and W states, \rho=p|GHZ><GHZ|+(1-p)|W><W|. Based on the Caratheodory theorem and the periodicity assumption, the possible optimal decomposition…

Quantum Physics · Physics 2017-08-23 Teng ma , Shao-Ming Fei

We discuss a generalization to 2 qubits of the standard Bloch sphere representation for a single qubit, in the framework of Hopf fibrations of high dimensional spheres by lower dimensional spheres. The single qubit Hilbert space is the…

Quantum Physics · Physics 2009-11-07 R. Mosseri , R. Dandoloff

For a general tripartite system in some pure state, an observer possessing any two parts will see them in a mixed state. By the consequence of Hughston-Jozsa-Wootters theorem, each basis set of local measurement on the third part will…

Quantum Physics · Physics 2014-12-01 Shaon Sahoo

Bipartite maximally entangled states have the property that the largest Schmidt coefficient reaches its lower bound. However, for multipartite states the standard Schmidt decomposition generally does not exist. We use a generalized Schmidt…

Quantum Physics · Physics 2009-11-12 Sayatnova Tamaryan , Tzu-Chieh Wei , DaeKil Park

We obtain the optimal scheme for estimating unknown qubit mixed states when an arbitrary number N of identically prepared copies is available. We discuss the case of states in the whole Bloch sphere as well as the restricted situation where…

Quantum Physics · Physics 2009-11-11 E. Bagan , M. A. Ballester , R. D. Gill , A. Monras , R. Munoz-Tapia

We represent a two-qubit density matrix in the basis of Pauli matrix tensor products, with the coefficients constituting a Bloch matrix, analogous to the single qubit Bloch vector. We find the quantum state positivity requirements on the…

Quantum Physics · Physics 2016-11-27 Omar Gamel

We present a generalization to 3-qubits of the standard Bloch sphere representation for a single qubit and of the 7-dimensional sphere representation for 2 qubits presented in Mosseri {\it et al.}\cite{Mosseri2001}. The Hilbert space of the…

Quantum Physics · Physics 2009-11-10 Bogdan A. Bernevig , Han-Dong Chen

The thesis includes the original results of our articles [30, 37, 40, 42, 51, 53, 75]. A method is developed to compute analytically entanglement measures of three-qubit pure states. Owing to it closed-form expressions are presented for the…

Quantum Physics · Physics 2014-03-11 Levon Tamaryan

We investigate the optimal convex approximation of the quantum state with respect to a set of available states. By isometric transformation, we have presented the general mathematical model and its solutions together with a triple…

Quantum Physics · Physics 2020-06-17 Xiao-Bin Liang , Bo Li , Liang Huang , Biao-Liang Ye , Shao-Ming Fei , Shi-Xiang Huang

Entanglement is an important concept in quantum information, quantum communication, and quantum computing. We provide a geometrical analysis of entanglement and separability for all the rank-2 quantum mixed states: complete analysis for the…

Quantum Physics · Physics 2017-03-09 Michel Boyer , Rotem Liss , Tal Mor

With any integer convex polytope $P\subset\midR^n$ we associate a multivariate hypergeometric polynomial whose set of exponents is $\midZ^{n}\cap P.$ This polynomial is defined uniquely up to a constant multiple and satisfies a holonomic…

Complex Variables · Mathematics 2016-12-05 D. V. Bogdanov , T. M. Sadykov

This thesis poses a selection of recent research of the author in a common context. It starts with a selected review on research concerning the role entanglement might play at quantum phase transitions and introduces measures for…

Quantum Physics · Physics 2012-02-08 A. Osterloh

The familiar Greenberger-Horne-Zeilinger (GHZ) states can be rewritten by entangling the Bell states for two qubits with a state of the third qubit, which is dubbed entangled entanglement. We show that in this way we obtain all 8…

Quantum Physics · Physics 2015-10-06 Gabriele Uchida , Reinhold A. Bertlmann , Beatrix C. Hiesmayr

In this paper, we study the $\alpha$th power monogamy properties related to the entanglement measure in bipartite states. The monogamy relations related to the $\alpha$th power of negativity and the Convex- Roof Extended Negativity are…

Quantum Physics · Physics 2018-08-02 Yu Luo , Yongming Li