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

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.

2012 ◽  
Vol 27 (06) ◽  
pp. 1250013 ◽  
Author(s):  
JUN ZHOU ◽  
SHUAI WANG ◽  
JUN SONG ◽  
HONG-YI FAN

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.


2020 ◽  
Vol 34 (33) ◽  
pp. 2050377
Author(s):  
Yan-Bei Cheng ◽  
Sheng-Guo Guan ◽  
Zu-Jian Wang ◽  
Xue-Xiang Xu

Two “amplified” quantum states, that is, amplified coherent state (ACS) and amplified squeezed vacuum (ASV), are considered in this paper by applying operator [Formula: see text] on coherent state (CS) and squeezed vacuum (SV), respectively. Here [Formula: see text] [Formula: see text] denotes a amplification factor and [Formula: see text]) denote the creation (annihilation) operator. Along these two lines, we make a comparative analysis of properties for ACS and ASV. The considered properties include density matrix elements, Wigner function, mean photon number, second-order autocorrelation function, and quadrature squeezing. We derive analytical expressions and make numerical simulations for all the properties. The noteworthy results include: (1) the ACS has antibunching and squeezing characters; (2) the ASV will have the bunching and antibunching effect in small initial squeezing.


1997 ◽  
Vol 11 (09n10) ◽  
pp. 399-406
Author(s):  
Norton G. de Almeida ◽  
Célia M. A. Dantas

The norder expressions for the squeezed and coherent states are derived as a natural generalization of the usual squeezed coherent and coherent states. The photon number distribution of n order of squeezed coherent states that are eigenstates of the operators [Formula: see text] is derived. The n order coherent state is a particular case of the states that we are now deriving. Some mathematical and quantum statistical properties of these states are discussed.


2013 ◽  
Vol 27 (23) ◽  
pp. 1350120 ◽  
Author(s):  
HONG-CHUN YUAN ◽  
YE-JUN XU ◽  
LEI CHEN ◽  
XUE-FEN XU

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.


2012 ◽  
Vol 26 (05) ◽  
pp. 1250027 ◽  
Author(s):  
M. K. TAVASSOLY ◽  
F. YADOLLAHI

The present study investigates the interaction of an equidistant three-level atom and a single-mode cavity field that has been initially prepared in a generalized coherent state. The atom–field interaction is considered to be, in general, intensity-dependent. We suppose that the nonlinearity of the initial generalized coherent state of the field and the intensity-dependent coupling between atom and field are distinctly chosen. Interestingly, an exact analytical solution for the time evolution of the state of atom–field system can be found in this general regime in terms of the nonlinearity functions. Finally, the presented formalism has been applied to a few known physical systems such as Gilmore–Perelomov and Barut–Girardello coherent states of SU(1,1) group, as well as a few special cases of interest. Mean photon number and atomic population inversion will be calculated, in addition to investigating particular non-classicality features such as revivals, sub-Poissonian statistics and quadratures squeezing of the obtained states of the entire system. Also, our results will be compared with some of the earlier works in this particular subject.


2018 ◽  
Vol 96 (12) ◽  
pp. 1365-1372
Author(s):  
Gang Ren ◽  
Jian-ming Du ◽  
Hai-jun Yu

In this paper, we construct and investigate the nonclassical properties of the squeezing and rotating coherent state (SRCS) via a generalized squeezed operator by introducing a novel parameter r. In a particular case r = 0, SRCS reduces to the normal squeezed coherent state (SCS). The influence of r is studied in terms of squeezing and quantum statistical properties. Our results show that in the SCS not only is squeezing enhanced but also is rotated by the parameter r. Our discussion about the fidelity between SRCS and SCS shows that the fidelity values decrease with increasing parameter r. The experimental scheme for producing SRCS is also given via a self-Kerr medium and non-degenerate parametric amplifier.


2004 ◽  
Vol 82 (8) ◽  
pp. 623-646 ◽  
Author(s):  
M H Naderi ◽  
M Soltanolkotabi ◽  
R Roknizadeh

By introducing a generalization of the (p, q)-deformed boson oscillator algebra, we establish a two-parameter deformed oscillator algebra in an infinite-dimensional subspace of the Hilbert space of a harmonic oscillator without first finite Fock states. We construct the associated coherent states, which can be interpreted as photon-added deformed states. In addition to the mathematical characteristics, the quantum statistical properties of these states are discussed in detail analytically and numerically in the context of conventional as well as deformed quantum optics. Particularly, we find that for conventional (nondeformed) photons the states may be quadrature squeezed in both cases Q = pq < 1, Q = pq > 1 and their photon number statistics exhibits a transition from sub-Poissonian to super-Poissonian for Q < 1 whereas for Q > 1 they are always sub-Poissonian. On the other hand, for deformed photons, the states are sub-Poissonian for Q > 1 and no quadrature squeezing occurs while for Q < 1 they show super-Poissonian behavior and there is a simultaneous squeezing in both field quadratures.PACS Nos.: 42.50.Ar, 03.65.–w


2014 ◽  
Vol 92 (9) ◽  
pp. 1016-1020
Author(s):  
Qian-Fan Chen ◽  
Hong-Yi Fan

For a general multiphoton annihilation operator, F = f(N)ap, where N = a†a, we find the explicit form of an operator, G†, which satisfies [F, G†] = 1. Based on the nonlinear realization of the SU(1,1) Lie algebra whose generators are [Formula: see text], [Formula: see text], and R0 = [N/p] + 1/2. We introduce the concept of intensity-dependent multiphoton squeezing and find that the state Lm(–yR†)|j⟩, 0 ≤ j ≤ p, where Lm(x) is a Laguerre polynomial, is a minimum uncertainty state for intensity-dependent multiphoton squeezing. We also construct the phase states for multiphoton operator, which turn out to be SU(1,1) generalized coherent states. Additionally, we show that the photon-added coherent state |α, m⟩ (m is a non-negative integer), which can be interpreted as a nonlinear coherent state, can be expressed as [Formula: see text] in the whole Fock space.


1981 ◽  
Vol 34 (4) ◽  
pp. 357
Author(s):  
GJ Troup ◽  
HS Perlman

A laser field may be idealized as a coherent state, but it is often more convenient to use Fock states fQr quantum electrodynamical calculations. A Fock state implies fluctuations in the field intensity, aptl a constant field intensity (coherent state) implies fluctuations in the photon number. Both these effects are discussed rigorously. When the average photon number tends to infinity, these different states become asymptotically indistinguishable.


2014 ◽  
Vol 29 (20) ◽  
pp. 1450108 ◽  
Author(s):  
Won Sang Chung

A new kind of charge coherent state called a Zp-graded charge coherent state is constructed by using the complex solution of the equation qp = 1. The p-1 charge operators are also explicitly constructed. We explicitly investigate some nonclassical properties for the Z3-graded charge coherent state.


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