English
Related papers

Related papers: Algorithm for characterizing stochastic local oper…

200 papers

Continuous-variable quantum states are of particular importance in various quantum information processing tasks including quantum communication and quantum sensing. However, a bottleneck has emerged with the fast increasing in size of the…

Quantum Physics · Physics 2021-10-13 Ye-Chao Liu , Jiangwei Shang , Xiangdong Zhang

Quantum entanglement and nonlocality are inequivalent notions: There exist entangled states that nevertheless admit local-realistic interpretations. This paper studies a special class of local-hidden-variable theories, in which the linear…

Quantum Physics · Physics 2017-11-17 Bin Yan

Classifying states as entangled or separable is a highly challenging task, while it is also one of the foundations of quantum information processing theory. This task is higly nontrivial even for relatively simple cases, such as two-qutrit…

Quantum Physics · Physics 2022-11-08 Marcin Wieśniak

The set of all separable quantum states is compact and convex. We focus on the two-qubit quanum system and study the boundary of the set. Then we give the criterion to determine whether a separable state is on the boundary. Some…

Quantum Physics · Physics 2007-05-23 Mingjun Shi , Jiangfeng Du

The necessary and sufficient conditions for the equivalence of arbitrary n-qubit pure quantum states under Local Unitary (LU) operations derived in [B. Kraus Phys. Rev. Lett. 104, 020504 (2010)] are used to determine the different…

Quantum Physics · Physics 2013-05-29 B. Kraus

We investigate macroscopic entanglement of quantum states in quantum computers, where we say a quantum state is entangled macroscopically if the state has superposition of macroscopically distinct states. The index $p$ of the macroscopic…

Quantum Physics · Physics 2007-05-23 Akihisa Ukena , Akira Shimizu

Geometric properties of the set of quantum entangled states are investigated. We propose an explicit method to compute the dimension of local orbits for any mixed state of the general K x M problem and characterize the set of effectively…

Quantum Physics · Physics 2009-11-06 Marek Kus , Karol Zyczkowski

The characterization of physical systems requires a comprehensive understanding of quantum effects. One aspect is a proper quantification of the strength of such quantum phenomena. Here, a general convex ordering of quantum states will be…

Quantum Physics · Physics 2015-06-24 J. Sperling , W. Vogel

Multipartite entanglement is one of the crucial resources in quantum information processing tasks such as quantum metrology, quantum computing and quantum communications. It is essential to verify not only the multipartite entanglement, but…

Quantum Physics · Physics 2024-06-12 Kai Wu , Zhihua Chen , Zhen-Peng Xu , Zhihao Ma , Shao-Ming Fei

Ever since entanglement was identified as a computational and cryptographic resource, effort has been made to find an efficient way to tell whether a given density matrix represents an unentangled, or separable, state. Essentially, this is…

Data Structures and Algorithms · Computer Science 2007-05-23 Lawrence M. Ioannou

We define what it means for a state in a convex cone of states on a space of observables to be generalized-entangled relative to a subspace of the observables, in a general ordered linear spaces framework for operational theories. This…

Quantum Physics · Physics 2009-11-11 Howard Barnum , Gerardo Ortiz , Rolando Somma , Lorenza Viola

We propose a new classification scheme for quantum entanglement based on topological links. This is done by identifying a non-rigid ring to a particle, attributing the act of cutting and removing a ring to the operation of tracing out the…

Quantum Physics · Physics 2018-04-09 Gonçalo M. Quinta , Rui André

We discuss the problem of determining whether the state of several quantum mechanical subsystems is entangled. As in previous work on two subsystems we introduce a procedure for checking separability that is based on finding state…

Quantum Physics · Physics 2007-05-23 Andrew C. Doherty , Pablo A. Parrilo , Federico M. Spedalieri

The efficient and reliable verification of quantum states plays a crucial role in various quantum information processing tasks. We consider the task of verifying entangled states using one-way and two-way classical communication and…

Quantum Physics · Physics 2019-12-09 Xiao-Dong Yu , Jiangwei Shang , Otfried Gühne

We focus on using an architecture similar to the $\beta$-Variational Autoencoder ($\beta$-VAE) to discriminate if a quantum state is entangled or separable based on measurements. We split the data into two sets, the set of local and…

Quantum Physics · Physics 2021-10-19 Nahum Sá , Itzhak Roditi

In the paper, we show that when a quantum state can be decomposed as a convex combination of locally orthogonal mixed states, its entanglement can be decomposed into the entanglement of these mixed states without losing them. The obtained…

Quantum Physics · Physics 2022-07-12 Sunho Kim , Junde Wu , Lin Zhang , Minhyung Cho

We present a description of entanglement in composite quantum systems in terms of symplectic geometry. We provide a symplectic characterization of sets of equally entangled states as orbits of group actions in the space of states. In…

Mathematical Physics · Physics 2016-01-19 Adam Sawicki , Alan Huckleberry , Marek Kuś

We provide quantitative bounds on the characterisation of multiparticle separable states by states that have locally symmetric extensions. The bounds are derived from two-particle bounds and relate to recent studies on quantum versions of…

Quantum Physics · Physics 2012-10-22 Fernando G. S. L. Brandao , Matthias Christandl

Quantum entanglement is at the heart of many tasks in quantum information. Apart from simple cases (low dimensions, few particles, pure states), however, the mathematical structure of entanglement is not yet fully understood. This tutorial…

Quantum Physics · Physics 2015-06-26 Dagmar Bruss

We introduce an operational entanglement classification of symmetric mixed states for an arbitrary number of qubits based on stochastic local operations assisted with classical communication (SLOCC operations). We define families of SLOCC…

Quantum Physics · Physics 2015-02-13 T. Bastin , P. Mathonet , E. Solano