TY - JOUR
T1 - Detection of non-Gaussian entangled states with an improved continuous-variable separability criterion
AU - Hertz, Anaelle
AU - Karpov, Evgueni
AU - Mandilara, Aikaterini
AU - Cerf, Nicolas J.
N1 - Funding Information:
This work was supported by the F.R.S.-FNRS Foundation under Project No. T.0199.13 and by the Belgian Federal IAP program under Project No. P7/35 Photonics@be. A.H. acknowledges financial support from the F.R.S.-FNRS Foundation and A.M. acknowledges financial support from the Ministry of Education and Science of the Republic of Kazakhstan (Contract No. 339/76-2015).
PY - 2016/3/22
Y1 - 2016/3/22
N2 - Currently available separability criteria for continuous-variable states are generally based on the covariance matrix of quadrature operators. The well-known separability criterion of Duan et al. [L. M. Duan, Phys. Rev. Lett. 84, 2722 (2000)PRLTAO0031-900710.1103/PhysRevLett.84.2722] and Simon [R. Simon, Phys. Rev. Lett. 84, 2726 (2000)PRLTAO0031-900710.1103/PhysRevLett.84.2726], for example, gives a necessary and sufficient condition for a two-mode Gaussian state to be separable, but leaves many entangled non-Gaussian states undetected. Here we introduce an improvement of this criterion that enables a stronger entanglement detection. The improved condition is based on the knowledge of an additional parameter, namely, the degree of Gaussianity, and exploits a connection with Gaussianity-bounded uncertainty relations [A. Mandilara and N. J. Cerf, Phys. Rev. A 86, 030102 (2012)PLRAAN1050-294710.1103/PhysRevA.86.030102]. We exhibit families of non-Gaussian entangled states whose entanglement remains undetected by the Duan-Simon criterion.
AB - Currently available separability criteria for continuous-variable states are generally based on the covariance matrix of quadrature operators. The well-known separability criterion of Duan et al. [L. M. Duan, Phys. Rev. Lett. 84, 2722 (2000)PRLTAO0031-900710.1103/PhysRevLett.84.2722] and Simon [R. Simon, Phys. Rev. Lett. 84, 2726 (2000)PRLTAO0031-900710.1103/PhysRevLett.84.2726], for example, gives a necessary and sufficient condition for a two-mode Gaussian state to be separable, but leaves many entangled non-Gaussian states undetected. Here we introduce an improvement of this criterion that enables a stronger entanglement detection. The improved condition is based on the knowledge of an additional parameter, namely, the degree of Gaussianity, and exploits a connection with Gaussianity-bounded uncertainty relations [A. Mandilara and N. J. Cerf, Phys. Rev. A 86, 030102 (2012)PLRAAN1050-294710.1103/PhysRevA.86.030102]. We exhibit families of non-Gaussian entangled states whose entanglement remains undetected by the Duan-Simon criterion.
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U2 - 10.1103/PhysRevA.93.032330
DO - 10.1103/PhysRevA.93.032330
M3 - Article
AN - SCOPUS:84963682658
VL - 93
JO - Physical Review A
JF - Physical Review A
SN - 2469-9926
IS - 3
M1 - 032330
ER -