The entanglement properties of non-Gaussian states prepared by photon subtraction from two-mode squeezed thermal states

2008 ◽  
Vol 372 (17) ◽  
pp. 2976-2979 ◽  
Author(s):  
Xiao-yu Chen
Keyword(s):  
Gaussian States ◽  
Photon Subtraction ◽  
Non Gaussian ◽  
Thermal States

scholarly journals ENTANGLEMENT CRITERION FOR COHERENT SUBTRACTION AND COHERENT ADDITION OF BIPARTITE CONTINUOUS VARIABLE STATES

2013 ◽  
Vol 11 (06) ◽  
pp. 1350060
Author(s):  
LI-ZHEN JIANG ◽  
XIAO-YU CHEN ◽  
TIAN-YU YE ◽  
FANG-YU HONG ◽  
LIANG-NENG WU
Keyword(s):  
Thermal Noise ◽  
Photon Number ◽  
Sufficient Conditions ◽  
Continuous Variable ◽  
Entangled State ◽  
Gaussian States ◽  
Non Gaussian ◽  
Entanglement Criterion ◽  
Entanglement Conditions ◽  
Thermal States

We study the entanglement conditions of two quite general classes of two-mode non-Gaussian states. Using computable cross norm and realignment criterion, we obtain the sufficient conditions of entanglement for coherently added or subtracted two-mode squeezed thermal states, and the sufficient condition of entanglement for any photon number entangled state (PNES) evolving in a thermal noise and amplitude damping channel.

scholarly journals Non-Gaussianity of Four-Photon Superpositions of Fock States

2021 ◽  
Vol 3 (3) ◽  
pp. 350-365
Author(s):  
Miguel Citeli de Freitas ◽  
Viktor V. Dodonov
Keyword(s):  
Fourth Order ◽  
Effective Temperature ◽  
Coherent States ◽  
Squeezed States ◽  
Gaussian States ◽  
Fock States ◽  
The Past ◽  
Fidelity Measure ◽  
Non Gaussian ◽  
Thermal States

We study two families of four-photon superpositions of the Fock states: even vacuum squeezed states (EVSS) and orthogonal-even coherent states (OECS). These families are distinguished due to several properties: for certain values of parameters, they give the fourth-order uncertainty products close to the known minimal value (which is lower than for the Gaussian states); they have equal dimensionless values of the second- and fouth-order moments of the coordinate and momentum for all values of parameters; they possess zero covariances for all values of parameters. Since these states are obviously non-Gaussian, we consider them as good candidates to compare several different measures of non-Gaussianity proposed by different authors for the past fifteen years. The reference Gaussian states in all examples are thermal states dependent on a single parameter (an effective temperature or the coordinate variance). We analyze the measures based on the normalized Hilbert–Schmidt distance and the relative entropy (introduced by Genoni–Paris–Banaszek), the fidelity measure (Ghiu–Marian–Marian) and its logarithmic analog (Baek–Nha), as well as the Mandilara–Karpov–Cerf “Gaussianity parameter”. These measures are compared with the kurtosis of the coordinate probability density and with the non-Gaussian behavior of the Wigner function.

scholarly journals Entanglement evaluation of non-Gaussian states generated by photon subtraction from squeezed states

2006 ◽  
Vol 73 (4) ◽  
Author(s):  
Akira Kitagawa ◽  
Masahiro Takeoka ◽  
Masahide Sasaki ◽  
Anthony Chefles
Keyword(s):  
Squeezed States ◽  
Gaussian States ◽  
Photon Subtraction ◽  
Non Gaussian

Teleportation improvement by noiseless linear amplification

2019 ◽  
Vol 19 (11&12) ◽  
pp. 935-951
Author(s):  
Hamza Adnane ◽  
Matteo G.A. Paris
Keyword(s):  
Coherent States ◽  
Large Range ◽  
Low Energy ◽  
Entangled State ◽  
Continuous Variables ◽  
Linear Amplification ◽  
Gaussian States ◽  
Linear Amplifier ◽  
Twin Beam ◽  
Non Gaussian

We address de-Gaussification of continuous variables Gaussian states by optimal non-deterministic noiseless linear amplifier (NLA) and analyze in details the properties of the amplified states. In particular, we investigate the entanglement content and the non-Gaussian character for the class of non-Gaussian entangled state obtained by using NL-amplification of two-mode squeezed vacua (twin-beam, TWB). We show that entanglement always increases, whereas improved EPR correlations are observed only when the input TWB has low energy. We then examine a Braunstein-Kimble-like protocol for the teleportation of coherent states, and compare the performances of TWB-based teleprotation with those obtained using NL-amplified resources. We show that teleportation fidelity and security may be improved for a large range of NLA parameters (gain and threshold).

scholarly journals Fidelity-based unitary operation-induced quantum correlation for continuous-variable systems

2019 ◽  
Vol 17 (04) ◽  
pp. 1950035
Author(s):  
Liang Liu ◽  
Xiaofei Qi ◽  
Jinchuan Hou
Keyword(s):  
Quantum Correlation ◽  
Quantum Correlations ◽  
Continuous Variable ◽  
Gaussian Channel ◽  
Simple Computation ◽  
Gaussian States ◽  
Text Mode ◽  
Computation Formula ◽  
Geometric Measurement ◽  
Thermal States

We propose a measure of nonclassical correlation [Formula: see text] in terms of local Gaussian unitary operations based on square of the fidelity [Formula: see text] for bipartite continuous-variable systems. This quantity is easier to be calculated or estimated and is a remedy for the local ancilla problem associated with the geometric measurement-induced nonlocality. A simple computation formula of [Formula: see text] for any [Formula: see text]-mode Gaussian states is presented and an estimation of [Formula: see text] for any [Formula: see text]-mode Gaussian states is given. For any [Formula: see text]-mode Gaussian states, [Formula: see text] does not increase after performing a local Gaussian channel on the unmeasured subsystem. Comparing [Formula: see text] in scale with other quantum correlations such as Gaussian geometric discord for two-mode symmetric squeezed thermal states reveals that [Formula: see text] is much better in detecting quantum correlations of Gaussian states.

scholarly journals Non-Gaussian postselection and virtual photon subtraction in continuous-variable quantum key distribution

2016 ◽  
Vol 93 (1) ◽  
Author(s):  
Zhengyu Li ◽  
Yichen Zhang ◽  
Xiangyu Wang ◽  
Bingjie Xu ◽  
Xiang Peng ◽  
...  
Keyword(s):  
Quantum Key Distribution ◽  
Virtual Photon ◽  
Key Distribution ◽  
Continuous Variable ◽  
Photon Subtraction ◽  
Non Gaussian
Sign in / Sign up

Export Citation Format

Share Document