NONCLASSICALITY AND DECOHERENCE OF PHOTON-ADDED THERMAL STATE

2010 ◽  
Vol 08 (08) ◽  
pp. 1373-1387 ◽  
Author(s):  
SHU-JING WANG ◽  
XUE-XIANG XU ◽  
SHAN-JUN MA
Keyword(s):  
Thermal State ◽  
Thermal Environment ◽  
Hermite Polynomials ◽  
Photon Number ◽  
Single Variable ◽  
State Characteristic ◽  
Number Formula ◽  
Analytical Expressions ◽  
Average Photon Number ◽  
Photon Number Distribution

Using the normally ordered form of thermal state characteristic of average photon number nc, we introduce the photon-added thermal state (PATS) and investigate its statistical properties, such as Mandel's Q-parameter, photon number distribution (PND), and Wigner function (WF). We then study its decoherence in a thermal environment with average thermal photon number [Formula: see text] and dissipative coefficient κ by deriving analytical expressions of the WF. The nonclassicality is discussed in terms of the negativity of the WF. It is found that the WF is always positive when [Formula: see text] for any number PATS. The expression for time evolution of the PND and the tomogram of PATS are also derived analytically, which are related to hypergeometric function and single variable Hermite polynomials.

PHOTON-NUMBER DISTRIBUTION AND WIGNER FUNCTION OF GENERALIZED PHOTON-MODULATED COHERENT STATE

2012 ◽  
Vol 27 (06) ◽  
pp. 1250013 ◽  
Author(s):  
JUN ZHOU ◽  
SHUAI WANG ◽  
JUN SONG ◽  
HONG-YI FAN
Keyword(s):  
Coherent State ◽  
Wigner Function ◽  
Hermite Polynomials ◽  
Photon Number ◽  
Single Variable ◽  
Normalization Factor ◽  
Nonclassical Properties ◽  
Number Distribution ◽  
Quantum Statistical ◽  
Photon Number Distribution

In this paper, we present the generalized photon-modulated coherent state (GPMCS) generated by repeatedly operating the combination of Bosonic creation and annihilation operators on the coherent state. It is found that the GPMCS is a Hermite-excited coherent state and its normalization factor is related to single-variable Hermite polynomials. Furthermore, some significant quantum statistical properties of the GPMCS are investigated, such as photon-number distribution (PND) and the Wigner function (WF). We find that the WF of the GPMCS has negative values when the generalized photon-modulation exists, which implies the nonclassical properties of the GPMCS.

SOME FEATURES OF SQUEEZED NEGATIVE BINOMIAL STATE

1992 ◽  
Vol 06 (03n04) ◽  
pp. 409-415 ◽  
Author(s):  
AMITABH JOSHI ◽  
S. V. LAWANDE
Keyword(s):  
Electromagnetic Field ◽  
Density Matrix ◽  
Wigner Function ◽  
Negative Binomial ◽  
Thermal State ◽  
Photon Number ◽  
Binomial State ◽  
Relationship Of ◽  
The Relationship ◽  
Photon Number Distribution

Properties of electromagnetic field in the squeezed negative binomial state are investigated in terms of photon number distribution and Wigner function. The relationship of the density matrix of the squeezed negative binomial state to the density matrix of the squeezed thermal state is shown explicitly. The possibility of generation of the negative binomial state is also discussed.

Nonclassicality of photon-modulated spin coherent states in the Holstein-Primakoff realization

2021 ◽  
Author(s):  
Xiaoyan Zhang ◽  
Jisuo Wang ◽  
Lei Wang ◽  
Xiangguo Meng ◽  
Baolong Liang
Keyword(s):  
Coherent States ◽  
Wigner Distribution ◽  
Hermite Polynomials ◽  
Photon Number ◽  
Spin Ladder ◽  
Bernoulli Distribution ◽  
Ladder Operators ◽  
Spin Number ◽  
Photon Number Distribution ◽  
Spin Coherent States

Abstract Two new photon-modulated spin coherent states (SCSs) are introduced by operating the spin ladder operators J ± on the ordinary SCS in the Holstein-Primakoff realization and the nonclassicality is exhibited via their photon number distribution, second-order correlation function, photocount distribution and negativity of Wigner distribution. Analytical results show that the photocount distribution is a Bernoulli distribution and the Wigner functions are only associated with two-variable Hermite polynomials. Compared with the ordinary SCS, the photon-modulated SCSs exhibit more stronger nonclassicality in certain regions of the photon modulated number k and spin number j, which means that the nonclassicality can be enhanced by selecting suitable parameters.

AMPLITUDE-SQUARED SQUEEZING IN THE m-PHOTON JAYNES-CUMMINGS MODEL WITH SQUEEZED FIELD INPUT

1992 ◽  
Vol 06 (13) ◽  
pp. 2409-2422 ◽  
Author(s):  
MUBEEN A. MIR ◽  
M.S.K. RAZMI
Keyword(s):  
Ground State ◽  
Photon Number ◽  
Vacuum State ◽  
Squeezed States ◽  
Initial Field ◽  
Squeezed Vacuum State ◽  
Squeezed Vacuum ◽  
Number Formula ◽  
Average Photon Number ◽  
Intensity Dependent Coupling

Amplitude-squared (AS) squeezing has been investigated for the m-photon Jaynes-Cummings model assuming the field to be initially in the squeezed states. The role played by intensity-dependent coupling has also been discussed. It has been shown that for the large initial average photon number [Formula: see text] with odd values of m, AS squeezing revokes permanently whereas with even values it recurs periodically. As m increases the revocation is hastened and the duration of occurrence decreases. Higher values of m for the initial field in a squeezed vacuum state can make one of the quadrature permanently squeezed. The AS squeezing behavior for two initial states of the atom, i.e., ground state versus excited state is also compared.

Photon-Number Distribution and Wigner Function of Generalized Squeezed Thermal State

2012 ◽  
Vol 51 (9) ◽  
pp. 2681-2689 ◽  
Author(s):  
Jun Zhou ◽  
Jun Song ◽  
Hao Yuan ◽  
Bo Zhang ◽  
Chuan-Mei Xie ◽  
...  
Keyword(s):  
Wigner Function ◽  
Thermal State ◽  
Photon Number ◽  
Number Distribution ◽  
Photon Number Distribution

scholarly journals Macroscopic displaced thermal field as the entanglement catalyst

2007 ◽  
Vol 7 (8) ◽  
pp. 775-781
Author(s):  
S.-B. Zheng
Keyword(s):  
Thermal Field ◽  
Cavity Mode ◽  
Thermal State ◽  
Atomic System ◽  
Photon Number ◽  
Resonant Interaction ◽  
Entangled State ◽  
Cavity Field ◽  
Average Photon Number

We show that entanglement of multiple atoms can arise via resonant interaction with a displaced thermal field with a macroscopic photon-number. The cavity field acts as the catalyst, which is disentangled with the atomic system after the operation. Remarkably, the entanglement speed does not decrease as the average photon-number of the mixed thermal state increases. The atoms may evolve to a highly entangled state even when the photon-number of the cavity mode approaches infinity.

SECOND-ORDER AND AMPLITUDE-SQUARED SQUEEZING OF THE TWO TWO-LEVEL ATOMS WITH SUPERPOSITION STATE PREPARATION

1993 ◽  
Vol 07 (26) ◽  
pp. 4439-4450 ◽  
Author(s):  
MUBEEN A. MIR
Keyword(s):  
Photon Number ◽  
Vacuum State ◽  
Second Order ◽  
Squeezed State ◽  
Superposition State ◽  
Initial Field ◽  
Squeezed Vacuum State ◽  
Coherent Field ◽  
Number Formula ◽  
Average Photon Number

An analysis of the second-order and amplitude-squared (AS) squeezing is presented for the two atoms prepared in a two-atom squeezed state using coherent and squeezed field inputs. The system produce strong sqeezing and superposition angle (θ) is more effective for small values of average photon number [Formula: see text] as compared to that of large one. The degree of squeezing of both types increases as θ increases for coherent field input with small [Formula: see text]. Some values of θ for the initial field in a squeezed-vacuum state with any value of input squeezing can make one of the quadrature of the both types of squeezing permanently squeezed for T≥0. For the initial field in a more general squeezed state, the second-order and AS squeezing behave randomly for different values of θ.

Squeezed coherent thermal state and its photon number distribution

1997 ◽  
Vol 6 (9) ◽  
pp. 681-689
Author(s):  
Li Yi-min ◽  
Xia Hui-rong ◽  
Wang Zu-geng ◽  
Xu Zai-xin
Keyword(s):  
Thermal State ◽  
Photon Number ◽  
Number Distribution ◽  
Photon Number Distribution
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