WIGNER FUNCTION EVOLUTION OF EXCITED EVEN AND ODD COHERENT STATE IN THERMAL ENVIRONMENT VIA THERMO ENTANGLED APPROACH

2013 ◽  
Vol 27 (23) ◽  
pp. 1350120 ◽  
Author(s):  
HONG-CHUN YUAN ◽  
YE-JUN XU ◽  
LEI CHEN ◽  
XUE-FEN XU
Keyword(s):  
Coherent State ◽  
Wigner Function ◽  
Decay Time ◽  
Arbitrary Number ◽  
Coherent States ◽  
Density Operator ◽  
Thermal Environment ◽  
New Approach ◽  
Non Gaussian ◽  
Analytical Expressions

We adopt a new approach, thermo entangled representation, to study time evolution of density operator in thermal environment. We then investigate the analytical expressions of Wigner function (WF) evolution of arbitrary number excited coherent states (ECSs) and excited even (odd) coherent states (EECSs, EOCSs) in thermal environment, respectively. In addition, their nonclassicality is numerically discussed by exploring the negativity of WF with decay time in thermal channel, respectively. It is found that WF loses its non-Gaussian nature and becomes Gaussian after long times.

Orthogonal state of coherent state based on Hermite-excited superposition operator: Production and Wigner function

2019 ◽  
Vol 33 (26) ◽  
pp. 1950320 ◽  
Author(s):  
Jian-Ming Wang ◽  
Zu-Jian Wang ◽  
Hong-Chun Yuan ◽  
Xue-Xiang Xu
Keyword(s):  
Coherent State ◽  
Wigner Function ◽  
Numerical Results ◽  
Interaction Parameters ◽  
Superposition Operator ◽  
Wigner Functions ◽  
Orthogonal State ◽  
Non Gaussian ◽  
Analytical Expressions

An orthogonal state of coherent state is produced by applying an orthogonalizer related with Hermite-excited superposition operator [Formula: see text]. Using some technique, we cleverly deal with the normalization and discuss the nonclassical and non-Gaussian characters of the orthogonal state. The analytical expressions for the Wigner functions of the orthogonal state are derived in detail. Numerical results show that the orthogonal state will exhibit its richly nonclassical and non-Gaussian character by changing the interaction parameters.

scholarly journals Detecting Nonclassicality and Non-gaussianity by the Wigner Function and Quantum Teleportation in Photon-added-and-subtracted Two Modes Pair Coherent State

2021 ◽  
Author(s):  
Minh Duc Truong ◽  
Chuong Sy Ho ◽  
Dat Quang Tran
Keyword(s):  
Coherent State ◽  
Wigner Function ◽  
Phase Difference ◽  
Quantum Teleportation ◽  
Entangled State ◽  
Pair Coherent State ◽  
Non Gaussian ◽  
Degree Of Entanglement

Abstract We introduce a new state called photon-added-and-subtracted two modes pair coherent state (PAASTMPCS) by simultaneously adding and subtracting photons to the different modes of a pair coherent state. Its nonclassical and non-Gaussian properties are strengthened via the negative values of its Wigner function as the numbers of adding and subtracting photons are increased. It indicates that the PAASTMPCS is an entangled state. When increasing the numbers of photon-added and photon-subtracted to a pair coherent state, the degree of entanglement in the PAASTMPCS is enhanced compared with the original pair coherent state. By using a PAASTMPCS as a non-Gaussian entangled resource, the quantum teleportation processes are studied in detail. It is shown that the number sum and phase difference measurements protocol is more appropriate than the orthogonal quadrature components measurements protocol in the quantum teleportation process of a coherent state.

Photon-catalyzed optical coherent states generated via a non-degenerate parametric amplifier with quantum-optical catalysis

2020 ◽  
Vol 98 (2) ◽  
pp. 119-124 ◽  
Author(s):  
Hong-Chun Yuan ◽  
Xue-Xiang Xu ◽  
Heng-Mei Li ◽  
Ye-Jun Xu ◽  
Xiang-Guo Meng
Keyword(s):  
Coherent State ◽  
Wigner Function ◽  
Coherent States ◽  
Laguerre Polynomial ◽  
Photon Number ◽  
Parametric Amplifier ◽  
Normalization Factor ◽  
Nonclassical Properties ◽  
Quadrature Squeezing ◽  
Quantum Optical

We theoretically generate a kind of photon-catalyzed optical coherent states (PCOCSs) by heralded interference between any photons and coherent state via a non-degenerate parametric amplifier, which is also just a Laguerre polynomial excited coherent state. Based on obtaining the probability of successfully detecting them (also the normalization factor), the nonclassical properties of the PCOCSs are analytically investigated according to autocorrelation function, quadrature squeezing, and the negativity of the Wigner function. It is found that the nonclassicality depends on the amplitude of the coherent state, the catalysis photon number, and amplifier parameter. The negative volume of their Wigner function can be enlarged by increasing the catalysis photon number. These parameters may be effectively used to improve and enhance the nonclassical characteristics.

scholarly journals EXPERIMENTAL QUANTIFICATION OF NON-GAUSSIANITY OF PHASE-RANDOMIZED COHERENT STATES

2012 ◽  
Vol 10 (08) ◽  
pp. 1241006 ◽  
Author(s):  
ALESSIA ALLEVI ◽  
STEFANO OLIVARES ◽  
MARIA BONDANI
Keyword(s):  
Experimental Investigation ◽  
Wigner Function ◽  
Coherent States ◽  
The Other ◽  
Fock States ◽  
Two Measures ◽  
Non Gaussian

We present the experimental investigation of the non-Gaussian nature of some mixtures of Fock states by reconstructing their Wigner function and exploiting two recently introduced measures of non-Gaussianity. In particular, we demonstrate the consistency between the different approaches and the monotonicity of the two measures for states belonging to the class of phase-randomized coherent states. Moreover, we prove that the exact behavior of one measure with respect to the other depends on the states under investigation and devise possible criteria to discriminate which measure is more useful for the characterization of the states in realistic applications.

scholarly journals Lie algebras and generalized thermal coherent states

2017 ◽  
Vol 32 (02n03) ◽  
pp. 1750015 ◽  
Author(s):  
Sergio Floquet ◽  
Marco A. S. Trindade ◽  
J. David M. Vianna
Keyword(s):  
Lie Groups ◽  
Lie Algebras ◽  
Wigner Function ◽  
Coherent States ◽  
Density Operator ◽  
Coset Space ◽  
Algebraic Formulation ◽  
Quantum Fidelity

In this paper, we developed an algebraic formulation for the generalized thermal coherent states with a thermofield dynamics approach for multi-modes, based on coset space of Lie groups. In particular, we applied our construction on SU(2) and SU(1,[Formula: see text]1) symmetries and we obtain their thermal coherent states and density operator. We also calculate their thermal quantum Fidelity and thermal Wigner function.

Comment on “Generation of a superposition of coherent states in a resonant cavity and its nonclassicality and decoherence”

2014 ◽  
Vol 92 (10) ◽  
pp. 1281-1282
Author(s):  
Gang Ren
Keyword(s):  
Coherent State ◽  
Wigner Function ◽  
Coherent States ◽  
Resonant Cavity ◽  
Analytic Expression

Arpita Ghosh and P.K. Das (Can. J. Phys. 86: 811 (2008) doi:10.1139/p08-013 ) derived an analytic expression for the Wigner function of a superposition of coherent state. We point out the incorrectness of this result.

Evolution of the photon-added coherent state in a laser channel

2012 ◽  
Vol 90 (6) ◽  
pp. 593-598 ◽  
Author(s):  
Jun Zhou ◽  
Jun Song ◽  
Hao Yuan ◽  
Hong-Yi Fan
Keyword(s):  
Coherent State ◽  
Density Operator ◽  
Gain Coefficient ◽  
Entangled State ◽  
State Representation ◽  
New Approach ◽  
Laser Process ◽  
Laser Channel ◽  
Thermo Entangled State Representation ◽  
Thermo Entangled State

We investigate the time evolution of a quantum state in the laser channel with cavity gain coefficient g and loss coefficient κ by virtue of the thermo entangled state representation. This is a new approach for solving master equations. We exactly calculate the evolving result of the photon-added coherent state (PACS) governed by the master equation describing the laser process, and the normal ordered form of the density operator in the laser channel is derived, based on which we calculate the Wigner function analytically and graphically. The corresponding law of the PACS evolution in the laser channel is evaluated.

Measure of non-Gaussianity for photon-added nonlinear coherent states

2018 ◽  
Vol 15 (09) ◽  
pp. 1850158
Author(s):  
K. Berrada ◽  
H. Eleuch
Keyword(s):  
Coherent State ◽  
Coherent States ◽  
Deformation Parameter ◽  
Critical Value ◽  
Statistical Properties ◽  
Noncommutative Space ◽  
Mandel’S Parameter ◽  
Generalized Coherent States ◽  
Non Gaussian

In this paper, we study the non-Gaussian character in generalized coherent states in the framework of a noncommutative space by adding photons to deformed coherent states, which is called the photon-added nonlinear coherent states (PANCSs). We find that the non-Gaussianity of PANCSs is enhanced with the increase of the photon-added number and it increases monotonically with the amplitude of the coherent states. Interestingly, we obtain that the maximal value of non-Gaussianity measure occurs at a certain critical value of the coherent state amplitude, where this critical value is determined by the kind of the deformation. Using the Mandel’s parameter, we examine the statistical properties for the PANCSs and show that the Mandel’s parameter may take positive and negative values depending on the choice of the amplitude and deformation parameter, exhibiting sub-Poissonian distribution and super-Poissonian distribution.

INTERACTION OF MESOSCOPIC JOSEPHSON JUNCTION WITH A SUCCESSIVE SQUEEZED COHERENT FIELD

2000 ◽  
Vol 14 (16) ◽  
pp. 609-618
Author(s):  
V. A. POPESCU
Keyword(s):  
Coherent State ◽  
Josephson Junction ◽  
Coherent States ◽  
Quantum Noise ◽  
Shapiro Steps ◽  
Superconducting Ring ◽  
Coherent Field ◽  
Current Voltage ◽  
Quantum Current ◽  
The Difference

Signal-to-quantum noise ratio for quantum current in mesoscopic Josephson junction of a circular superconducting ring can be improved if the electromagnetic field is in a successive squeezed coherent state. The mesoscopic Josephson junctions can feel the difference between the successive squeezed coherent states and other types of squeezed coherent states because their current–voltage Shapiro steps are different. We compare our method with another procedure for superposition of two squeezed coherent states (a squeezed even coherent state) and consider the effect of different large inductances on the supercurrent.

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