Detecting and estimating continuous-variable entanglement by local orthogonal observables

Abstract

Entanglement detection and estimation are fundamental in quantum information science. Compared with discrete-variable states, for which lots of efficient entanglement detection criteria and lower bounds of entanglement measures have been proposed, the continuous-variable entanglement is much less understood. Here we shall present a family of entanglement witnesses based on continuous-variable local orthogonal observables (CVLOOs) to detect and estimate entanglement of Gaussian and non-Gaussian states, especially for bound entangled states. By choosing an optimal set of CVLOOs our entanglement witness is equivalent to the realignment criterion and can be used to detect bound entanglement of a class of 2+2 mode Gaussian states. Via our entanglement witness, lower bounds of two typical entanglement measures for arbitrary two-mode continuous-variable states are obtained.

11 pages, 1 figure

References in corpus (20)

• Entanglement detection
• Necessary and sufficient condition for non-zero quantum discord
• Concurrence of arbitrary dimensional bipartite quantum states
• Gaussian measures of entanglement versus negativities: the ordering of two-mode Gaussian states
• Estimating entanglement measures in experiments
• Covariance matrices and the separability problem
• Entanglement and permutational symmetry
• Optimal entanglement witnesses based on local orthogonal observables
• Entanglement criteria based on local uncertainty relations are strictly stronger than the computable cross norm criterion
• Unifying several separability conditions using the covariance matrix criterion
• Entanglement detection beyond the cross-norm or realignment criterion
• Uncertainty inequalities as entanglement criteria for negative partial-transpose states
• Comment on ``Inseparability Criteria for Continuous Bipartite Quantum States''
• Lower bounds on entanglement measures from incomplete information
• Preparing the bound instance of quantum entanglement
• Entanglement condition via su(2) and su(1,1) algebra using Schr{ö}dinger-Robertson uncertainty relation
• Optimal estimation of entanglement in optical qubit systems
• Estimating entanglement of unknown states
• Observable estimation of entanglement of formation and quantum discord for bipartite mixed quantum states
• Detection of bound entanglement in continuous variable systems

Cited by in corpus (22)

• Detecting entanglement in quantum many-body systems via permutation moments
• Experimentally accessible lower bounds for genuine multipartite entanglement and coherence measures
• Contextuality in phase space
• Entanglement sensitivity to signal attenuation and amplification
• Quantifying entanglement of a two-qubit system via measurable and invariant moments of its partially transposed density matrix
• Partial transpose as a direct link between concurrence and negativity
• Design and Experimental Performance of Local Entanglement Witness Operators
• Entanglement and nonclassicality: A mutual impression
• Relating the Entanglement and Optical Nonclassicality of Multimode States of a Bosonic Quantum Field
• Hierarchies of multipartite entanglement for continuous-variable states
• Analyzing quantum entanglement with the Schmidt decomposition in operator space
• Evaluation of entanglement measures by a single observable
• Gaussian Continuous-Variable Isotropic State
• Triangle inequalities in coherence measures and entanglement concurrence
• Gaussian entanglement witness and refined Werner-Wolf criterion for continuous variables
• Realignment separability criterion assisted with filtration for detecting continuous-variable entanglement
• Quantum entanglement in phase space
• Not all entangled states are useful for ancilla-assisted quantum process tomography
• Uncertainty relations between quantum Fisher information and entanglement monotones
• Witnessing genuine multipartite entanglement in phase space with controlled Gaussian unitaries
• Sufficient Wigner Negativity Implies Genuine Multipartite Entanglement
• Detecting strongly non-Gaussian entanglement