English
Related papers

Related papers: Bounds on mixed state entanglement

200 papers

We develop a statistical framework, based on a manifold learning embedding, to extract relevant features of multipartite entanglement structures of mixed quantum states from the measurable correlation data of a quantum computer. We show…

Quantum Physics · Physics 2024-07-26 Eric Brunner , Aaron Xie , Gabriel Dufour , Andreas Buchleitner

In this paper, we present a new approach to study genuine tripartite entanglement existing in $(2\times 2\times n)-$dimensional quantum pure states. By utilizing the approach, we introduce a particular quantity to measure genuine tripartite…

Quantum Physics · Physics 2008-12-05 Chang-shui Yu , He-shan Song , Ya-hong Wang

The entanglement quantified by negativity of pure bipartite superposed states is studied. We show that if the entanglement is quantified by the concurrence two pure states of high fidelity to one another still have nearly the same…

Quantum Physics · Physics 2007-09-06 Yong-Cheng Ou , Heng Fan

Quantum entanglement cannot be unlimitedly shared among arbitrary number of qubits. Larger the number of entangled pairs in an N-qubit system, smaller the degree of bi-partite entanglement is. We analyze a system of N qubits in which an…

Quantum Physics · Physics 2009-11-06 Masato Koashi , Vladimir Buzek , Nobuyuki Imoto

We propose the necessary and sufficient condition for the presence of quantum entanglement in arbitrary symmetric pure states of two-level atomic systems. We introduce a parameter to quantify quantum entanglement in such systems. We express…

Quantum Physics · Physics 2011-11-22 Ram Narayan Deb

We derive an explicit formula for an entanglement measure of mixed quantum states in a multi-level atom interacting with a cavity field within the framework of the quantum mutual entropy. We describe its theoretical basis and discuss its…

Quantum Physics · Physics 2007-05-23 Mahmoud Abdel-Aty , M. R. B. Wahiddin , A. -S. F. Obada

We present an approach to characterize genuine multiparticle entanglement using appropriate approximations in the space of quantum states. This leads to a criterion for entanglement which can easily be calculated using semidefinite…

Quantum Physics · Physics 2011-05-13 Bastian Jungnitsch , Tobias Moroder , Otfried Gühne

We introduce a general framework for detecting genuine multipartite entanglement and non full-separability in multipartite quantum systems of arbitrary dimensions based on correlation tensors. Regarding genuine multipartite entanglement our…

Quantum Physics · Physics 2011-12-08 Julio I. de Vicente , Marcus Huber

Recently, a technique known as quantum symmetry test has gained increasing attention for detecting bipartite entanglement in pure quantum states. In this work we show that, beyond qualitative detection, a family of well-defined measures of…

Quantum Physics · Physics 2025-11-12 Xiaoyu Liu , Jordi Tura , Albert Rico

We present an analytical approach to evaluate the geometric measure of multiparticle entanglement for mixed quantum states. Our method allows the computation of this measure for a family of multiparticle states with a certain symmetry and…

Quantum Physics · Physics 2016-04-05 Lars Erik Buchholz , Tobias Moroder , Otfried Gühne

While the detection of entanglement has been proved already to be quite a difficult task, experimental quantification of entanglement is even more challenging. In this work, we derive an analytical lower bound for the concurrence of a…

Quantum Physics · Physics 2011-04-07 Zhi-Hao Ma , Zhi-Hua Chen , Jing-Ling Chen

We present an inequality for detecting entanglement and distillability of arbitrary dimensional bipartite systems. This inequality provides a sufficient condition of entanglement for bipartite mixed states, and a necessary and sufficient…

Quantum Physics · Physics 2013-07-04 Ming-Jing Zhao , Ting-Gui Zhang , Xianqing Li-Jost , Shao-Ming Fei

We propose to characterize multipartite entanglement of pure states as local unitary transformations acting on some parts of a system that can be undone by local unitary transformations acting on other parts. This leads to a definition of…

Quantum Physics · Physics 2025-07-08 Xiaole Jiang , Daniel Kabat , Gilad Lifschytz , Aakash Marthandan

For a given pure state of a composite quantum system we analyze the product of its projections onto a set of locally orthogonal separable pure states. We derive a bound for this product analogous to the entropic uncertainty relations. For…

Quantum Physics · Physics 2015-05-28 Łukasz Rudnicki , Paweł Horodecki , Karol Życzkowski

We theoretically derive the probability densities of the entanglement measures of a pure non-ergodic many-body state, represented in a bipartite product basis and with its reduced density matrix described by a generalized, multi-parametric…

Quantum Physics · Physics 2024-12-11 Devanshu Shekhar , Pragya Shukla

We use concepts from quantum cryptography to relate the entanglement in many-body mixed states to standard correlation functions. If a system can be used as a resource for distilling private keys -- random classical bits that are shared by…

Quantum Physics · Physics 2026-03-13 Samuel J. Garratt , Max McGinley

Using the subtraction approach, we give the bipartite mixed state entanglement entropy in thermal $\text{CFT}_2$. With these entanglement entropies, we examine in detail the holographic duals of different entangling configurations…

High Energy Physics - Theory · Physics 2025-09-01 Xin Jiang , Haitang Yang , Zilin Zhao

Bound entanglement with a nonpositive partial transposition (NPT) does not exist. For any NPT entangled state a distillation procedure can be based on a certain number of copies. This number is the minimal Schmidt rank of a pure state…

Quantum Physics · Physics 2009-11-02 J. Sperling , W. Vogel

We study the monogamy and polygamy inequalities of unified entanglement in multipartite quantum systems. We first derive the monogamy inequality of unified-$(q, s)$ entanglement for multi-qubit states under arbitrary bipartition, and then…

Quantum Physics · Physics 2022-05-16 Mei-Ming Zhang , Naihuan Jing , Hui Zhao

In this paper, we investigate a genuine multipartite entanglement measure based on the geometric method. This measure arrives at the maximal value for the absolutely maximally entangled states and has desirable properties for quantifying…

Quantum Physics · Physics 2022-06-07 Xian Shi