English
Related papers

Related papers: Entanglement detection via third-order local invar…

200 papers

We present several measurement schemes for accessing separability criteria for continuous-variable bipartite quantum systems. Starting from moments of the bosonic mode operators, criteria suitable to witness entanglement are expressed in…

Quantum Physics · Physics 2023-08-28 Célia Griffet , Tobias Haas , Nicolas J. Cerf

We derive a family of entanglement criteria for continuous variable systems based on the R\'enyi entropy of complementary distributions. We show that these entanglement witnesses can be more sensitive than those based on second-order…

Quantum Physics · Physics 2015-05-18 A. Saboia , F. Toscano , S. P. Walborn

A general framework is developed for separating classical and quantum correlations in a multipartite system. Entanglement is defined as the difference in the correlation information encoded by the state of a system and a suitably defined…

Quantum Physics · Physics 2007-05-23 M. Hossein Partovi

Our study employs a connected correlation matrix to quantify Quantum Entanglement. The matrix encompasses all necessary measures for assessing the degree of entanglement between particles. We begin with a three-qubit state and involve…

Quantum Physics · Physics 2023-12-06 Xingyu Guo , Chen-Te Ma

As one of the most profound features of quantum mechanics, entanglement is a vital resource for quantum information processing. Inspired by the recent work on PT-moments and separablity [Phys. Rev. Lett. {\bf 127}, 060504 (2021)], we…

Quantum Physics · Physics 2024-02-21 Xiaofen Huang , Naihuan Jing

We present a new technique to reduce the expected number of measurements to declare an unknown quantum state as entangled. Our method is based on the geometric criterion and so requires only local Pauli measurements. Using concentration of…

Quantum Physics · Physics 2017-09-13 Bingjie Wang , Stephen Brierley

Quantifying quantum mechanical uncertainty is vital for the increasing number of experiments that reach the uncertainty limited regime. We present a method for computing tight variance uncertainty relations, i.e., the optimal…

Quantum Physics · Physics 2017-11-01 René Schwonnek , Lars Dammeier , Reinhard F. Werner

Entanglement is a purely quantum mechanical phenomenon and thus it has no classical analog. On the other hand, coherence is a well-known phenomenon in classical optics and in quantum mechanics. Recent research shows that quantum coherence…

Quantum Physics · Physics 2023-02-14 Anu Kumari , Satyabrata Adhikari

Continuous variables systems find valuable applications in quantum information processing. To deal with an infinite-dimensional Hilbert space, one in general has to handle large numbers of discretized measurements in tasks such as…

We exactly evaluate a number of multipartite entanglement measures for a class of graph states, including d-dimensional cluster states (d = 1,2,3), the Greenberger-Horne-Zeilinger states, and some related mixed states. The entanglement…

Quantum Physics · Physics 2007-07-10 Damian Markham , Akimasa Miyake , Shashank Virmani

We introduce a multi-mode squeezing coefficient to characterize entanglement in $N$-partite continuous-variable systems. The coefficient relates to the squeezing of collective observables in the $2N$-dimensional phase space and can be…

Quantum Physics · Physics 2017-07-17 Manuel Gessner , Luca Pezzè , Augusto Smerzi

Entanglement detection is a fundamental task in quantum information science, serving as a cornerstone for quantum benchmarking and foundational studies. With an increasing qubit number that can be effectively controlled, there is a pressing…

We investigate the joint (separable) numerical range of multiple measurements, i.e., the regions of expectation values accessible with (separable) quantum states for given observables. This not only enables efficient entanglement detection,…

Quantum Physics · Physics 2021-11-03 Timo Simnacher , Jakub Czartowski , Konrad Szymański , Karol Życzkowski

The quantification of the entanglement present in a physical system is of para\-mount importance for fundamental research and many cutting-edge applications. Currently, achieving this goal requires either a priori knowledge on the system or…

We investigate how stabilizer theory can be used for constructing sufficient conditions for entanglement. First, we show how entanglement witnesses can be derived for a given state, provided some stabilizing operators of the state are…

Quantum Physics · Physics 2007-05-23 Geza Toth , Otfried Guehne

For general bipartite mixed states, a sufficient and necessary mathematical condition for certifying entanglement and/or (Bell) non-locality remains unknown. In this paper, we examine this question for a broad and physically relevant class…

Quantum Physics · Physics 2025-03-24 Alexander Bernal , J. Alberto Casas , Juan Falceto

We present in detail a statistical approach for the reference-frame-independent detection and characterization of multipartite entanglement based on moments of randomly measured correlation functions. We start by discussing how the…

Quantum Physics · Physics 2020-09-23 Andreas Ketterer , Nikolai Wyderka , Otfried Gühne

Entanglement measures quantify nonclassical correlations present in a quantum system, but can be extremely difficult to calculate, even more so, when information on its state is limited. Here, we consider broad families of entanglement…

Quantum Physics · Physics 2021-07-07 Matteo Fadel , Ayaka Usui , Marcus Huber , Nicolai Friis , Giuseppe Vitagliano

We experimentally detect entanglement in modular position and momentum variables of photon pairs which have passed through $D$-slit apertures. We first employ an entanglement criteria recently proposed in [Phys. Rev. Lett. {\bf 106}, 210501…

Quantum Physics · Physics 2015-06-11 M. A. D. Carvalho , J. Ferraz , G. F. Borges , P. L. de Assis , S. Pádua , S. P. Walborn

We report an experiment in which one determines, with least tomographic effort, whether an unknown two-photon polarization state is entangled or separable. The method measures whole families of optimal entanglement witnesses. We introduce…

Quantum Physics · Physics 2014-10-29 Jibo Dai , Yink Loong Len , Yong Siah Teo , Berthold-Georg Englert , Leonid A. Krivitsky