English
Related papers

Related papers: Certifying Separability in Symmetric Mixed States,…

200 papers

After introducing the partially separable concept, we proved the equivalence between the partial separability of a given $m$-partite subsystem with $m$ qubits and the purity of states of this $m$-partite subsystem for a pure state in…

Quantum Physics · Physics 2007-05-23 An Min Wang

The positive partial transpose test is one of the main criteria for detecting entanglement, and the set of states with positive partial transpose is considered as an approximation of the set of separable states. However, we do not know to…

Quantum Physics · Physics 2015-05-13 Salman Beigi , Peter W. Shor

We present separability criteria based on local symmetric measurements. These experimental plausible criteria are shown to be more efficient in detecting entanglement than the current counterparts by detailed examples. Furthermore, we…

Quantum Physics · Physics 2025-12-30 Yu Lu , Hao-Fan Wang , Meng Su , Zhi-Xi Wang , Shao-Ming Fei

We present a framework for deciding whether a quantum state is separable or entangled using covariance matrices of locally measurable observables. This leads to the covariance matrix criterion as a general separability criterion. We…

Quantum Physics · Physics 2008-12-03 Oleg Gittsovich , Otfried Gühne , Philipp Hyllus , Jens Eisert

The recent proposed realignment separability criterion for mixed is analyzed. We identify the essential part of this criterion is a swap operator followed by a partial transposition. Then we analyze the separability criterion of permutation…

Quantum Physics · Physics 2007-05-23 Heng Fan

We investigate the detection of entanglement in $n$-partite quantum states. We obtain practical separability criteria to identify genuinely entangled and non-separable mixed quantum states. No numerical optimization or eigenvalue evaluation…

Quantum Physics · Physics 2010-12-15 Ting Gao , Yan Hong

We give separability criteria for general multi-qubit states in terms of diagonal and anti-diagonal entries. We define two numbers which are obtained from diagonal and anti-diagonal entries, respectively, and compare them to get criteria.…

Quantum Physics · Physics 2018-12-10 Kil-Chan Ha , Kyung Hoon Han , Seung-Hyeok Kye

In this paper we present the necessary and sufficient conditions of separability for multipartite pure states. These conditions are very simple, and they don't require Schmidt decomposition or tracing out operations. We also give a…

Quantum Physics · Physics 2012-05-08 D. Li , H. Huang , X. Li

We derive a combinatorial criterion for detecting k-separability of N-partite Dicke states. The criterion is efficiently computable and implementable without full state tomography. We give examples in which the criterion succeeds, where…

Quantum Physics · Physics 2015-11-03 Zhihua Chen , Zhihao Ma , Ting Gao , Simone Severini

Quantum entanglement has been regarded as one of the key physical resources in quantum information sciences. However, the determination of whether a mixed state is entangled or not is generally a hard issue, even for the bipartite system.…

Quantum Physics · Physics 2018-02-15 Jun-Li Li , Cong-Feng Qiao

The concept of entanglement and separability of quantum states is relevant for several fields in physics. Still, there is a lack of effective operational methods to characterise these features. We propose a method to certify quantum…

Quantum Physics · Physics 2024-03-06 Ties-A. Ohst , Xiao-Dong Yu , Otfried Gühne , H. Chau Nguyen

The separability detecting problem of mixed states is one of the fundamental problems in quantum information theory. In the last 20 years, almost all methods are based on the sufficient or necessary conditions for entanglement. However, in…

Quantum Physics · Physics 2020-07-15 Ying Li , Guyan Ni

Separability from the spectrum is a significant and ongoing research topic in quantum entanglement. In this study, we investigate properties related to absolute separability from the spectrum in qudits-qudits states in the bipartite states…

Quantum Physics · Physics 2024-08-22 Liang Xiong , Nung-Sing Sze

In this paper, an intuitive approach is employed to generalize the full separability criterion of tripartite quantum states of qubits to the higher-dimensional systems (Phys. Rev. A \textbf{72}, 022333 (2005)). A distinct characteristic of…

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

Hilbert-Schmidt (HS) decompositions are employed for analyzing systems of n-qubits, and a qubit with a qudit. Negative eigenvalues, obtained by partial-transpose (PT) plus local unitary transformations (PTU) for one qubit from the whole…

Quantum Physics · Physics 2016-06-29 Y. Ben-Aryeh , A. Mann

Randomized measurements access nonlinear functionals without full tomography, yet turning third-order local single-copy data into a strong entanglement test remains difficult. We convert the reduction criterion into an experimentally…

Quantum Physics · Physics 2026-04-16 Giovanni Scala , Gniewomir Sarbicki

We extend the classification of mixed states of quantum systems composed of arbitrary number of subsystems of arbitrary dimensions. This extended classification is complete in the sense of partial separability and gives 1+18+1 partial…

Quantum Physics · Physics 2012-10-03 Szilárd Szalay , Zoltán Kökényesi

We introduce a sequence of numerical tests that can determine the entanglement or separability of a state even when there is not enough information to completely determine its density matrix. Given partial information about the state in the…

Quantum Physics · Physics 2012-12-14 Federico M. Spedalieri

Based on the ranks of reduced density matrices, we derive necessary conditions for the separability of multiparticle arbitrary-dimensional mixed states, which are equivalent to sufficient conditions for entanglement. In a similar way we…

Quantum Physics · Physics 2007-05-23 Bo Chong , Hellmut Keiter , Joachim Stolze

It is known that realignment crierion is necessary but not a sufficient criterion for lower as well as higher dimensional system. In this work, we first consider a two-qubit system and derived the necessary and sufficient condition based on…

Quantum Physics · Physics 2022-05-02 Shweta Kalson , Anchal Singh , Satyabrata Adhikari