Evolution law of photocounting probability in a diffusion channel

We find that in optical fields' diffusion process, the l-photocounting probability formula [Formula: see text] at time t = 0 should be generalized to a new formula [Formula: see text] at time t, where ρ(0) is the initial density operator of the field, Ll is the Laguerre polynomial, : : denotes normal ordering, and ξ is the quantum efficiency of the photocounting detector. This new formula brings much convenience for different ρ0, because for deriving [Formula: see text] there is no need to derive the corresponding ρ(t) in the diffusion channel.

Download Full-text

Photon-added chaotic field and its damping in a thermo enviroment

Canadian Journal of Physics ◽

10.1139/cjp-2014-0405 ◽

2015 ◽

Vol 93 (4) ◽

pp. 456-459 ◽

Cited By ~ 1

Author(s):

Hong-Yi Fan ◽

Rui He

Keyword(s):

Field Theory ◽

Quantum Field Theory ◽

Density Operator ◽

Laguerre Polynomial ◽

Quantum Field ◽

Initial Field ◽

Normal Ordering ◽

Chaotic Field ◽

Amplitude Damping Channel ◽

Time Evolution Equation

We propose a new photon field in quantum field theory, named Laguerre-polynomial-weighted chaotic field. This field will emerge when an initial photon-added chaotic field, which is represented by its density operator [Formula: see text], dissipates in an amplitude damping channel described by time evolution equation [Formula: see text], where κ is a damping coefficient, that is, the initial field will evolve into [Formula: see text] with [Formula: see text], where Ls is the s-order Laguerre-polynomial, and : : denotes normal ordering. We employ the method of summation within an ordered product of operators to obtain our result.

Download Full-text

Time evolution law of the Laguerre-polynomial-weighted chaotic photon field in an amplitude-damping channel

Canadian Journal of Physics ◽

10.1139/cjp-2014-0278 ◽

2015 ◽

Vol 93 (3) ◽

pp. 283-289 ◽

Cited By ~ 2

Author(s):

Cheng Da ◽

Qian-Fan Chen ◽

Peng-Fei Zhang ◽

Hong-Yi Fan

Keyword(s):

Decay Rate ◽

Time Evolution ◽

Generating Function ◽

Density Operator ◽

Laguerre Polynomial ◽

Hermite Polynomials ◽

Evolution Law ◽

Amplitude Damping ◽

Photon Field ◽

Amplitude Damping Channel

We examine how a Laguerre-polynomial-weighted chaotic photon field (LPWCPF), whose density operator is [Formula: see text], evolves in an amplitude-damping channel. By using a newly derived generating function of two-variable Hermite polynomials we obtain the evolution law of LPWCPF, which turns out to be a new LPWCPF with a new parameter, depending on 1 − e−2κt, where κ represents decay rate. The technique of integration (summation) within an ordered product of operators is used in our discussions.

Download Full-text

Time evolution law of a two-mode squeezed light field undergoing through a twin-diffusion-channel

Chinese Physics B ◽

10.1088/1674-1056/ac140b ◽

2021 ◽

Author(s):

Yu Hai-Jun ◽

Fan Hong-Yi

Keyword(s):

Time Evolution ◽

Light Field ◽

Diffusion Channel ◽

Evolution Law ◽

Squeezed Light

Download Full-text

THE SU(2) NONLINEAR σ MODEL IN 2+1 DIMENSIONS: PERTURBATION THEORY IN A POLYNOMIAL FORMULATION

International Journal of Modern Physics A ◽

10.1142/s0217751x95000796 ◽

1995 ◽

Vol 10 (11) ◽

pp. 1655-1670 ◽

Cited By ~ 1

Author(s):

C.D. FOSCO ◽

T. MATSUYAMA

Keyword(s):

Perturbation Theory ◽

Vector Field ◽

Scattering Amplitudes ◽

Loop Order ◽

Normal Ordering ◽

First Order ◽

Feynman Rules ◽

Field L ◽

Polynomial Formulation ◽

Full Propagator

We construct a perturbation theory for the SU(2) nonlinear σ model in 2+1 dimensions using a polynomial, first-order formulation, where the variables are a non-Abelian vector field Lμ [the left SU(2) current], and a non-Abelian pseudovector field θμ, which imposes the condition Fμv(L)=0. The coordinates on the group do not appear in the Feynman rules, but their scattering amplitudes are easily related to those of the currents. We show that all the infinities affecting physical amplitudes at one-loop order can be cured by normal-ordering, presenting the calculation of the full propagator as an example of an application.

Download Full-text

Energy variation of mesoscopic L–C electric circuit in external electromagnetic field

International Journal of Modern Physics B ◽

10.1142/s0217979215501696 ◽

2015 ◽

Vol 29 (23) ◽

pp. 1550169 ◽

Cited By ~ 1

Author(s):

Xing-Lei Xu ◽

Xiu-Xia Wang ◽

Hong-Yi Fan

Keyword(s):

Electromagnetic Field ◽

Energy Flow ◽

Diffusion Rate ◽

Initial Density ◽

Electric Circuit ◽

External Electromagnetic Field ◽

Entangled State ◽

Diffusion Channel ◽

Variation Formula ◽

Energy Variation

In this paper, we investigate energy variation of mesoscopic L–C electric circuit in external electromagnetic field (EMF) due to the energy flow of EMF, we consider this a diffusion process governed by the master equation for diffusion channel with the diffusion rate being determined by the energy flow of EMF. By using the entangled state representation and the method of integration within ordered product of operators we derive time evolution law of the initial density operator of the circuit and the energy variation formula.

Download Full-text

Quantum Statistical Derivation of the Ginzburg–Landau Equation.

International Journal of Modern Physics B ◽

10.1142/s0217979298000077 ◽

1998 ◽

Vol 12 (01) ◽

pp. 99-111 ◽

Cited By ~ 4

Author(s):

Shigeji Fujita ◽

Salvador Godoy

Keyword(s):

Density Operator ◽

Cooper Pair ◽

Energy Gap ◽

Landau Equation ◽

Field Operator ◽

Equation Of Motion ◽

Condensation Energy ◽

Ginzburg Landau ◽

Quantum Statistical ◽

New Formula

The Cooper pair (pairon) field operator ψ†(r,t) changes, following Heisenberg's equation of motion. If the Hamiltonian ℋ contains pairon kinetic energies h0, a condensation energy α(<0) and a repulsive point-like interpairon interaction βδ(r1-r2), β>0, the evolution equation for ψ is nonlinear, from which we obtain the Ginzburg–Landau (GL) equation: [Formula: see text] for the GL wave function Ψσ(r)≡ <r| n1/2|σ>, where σ denotes the state of the condensed pairons, and n the density operator. The GL equation with α=-εg(T) is shown to hold for all temperatures (T) below Tc, where εg is the pairon energy gap. Its equilibrium solution yields that the condensed pairon density n0(T)=|Ψσ(r)|2 is proportional to εg(T). The original GL T-dependence of the expansion parameters near Tc:α=-b(Tc-T), β= constant is justified. With the assumption of h0, a new formula for the penetration depth is obtained.

Download Full-text

The influence of larval crowding on the development time of populations of Drosophila melanogaster on chemically defined medium

Canadian Journal of Zoology ◽

10.1139/z68-068 ◽

1968 ◽

Vol 46 (3) ◽

pp. 493-497 ◽

Cited By ~ 4

Author(s):

Barrie Cohen

Keyword(s):

Drosophila Melanogaster ◽

Amino Acid ◽

Acid Medium ◽

Initial Density ◽

Defined Medium ◽

Chemically Defined Medium ◽

Complex Situation ◽

Insect Populations ◽

Larval Crowding ◽

New Formula

Work with Drosophila melanogaster, cultured on chemically defined amino acid medium, showed that at extreme larval densities the average time to pupation and eclosion of the survivors of the insect population is a decreasing function of the initial density. Evidence is presented which illustrates that at extreme densities larval development rate is significantly increased. Possible causes of this phenomenon are cited. It is stressed, however, that a very complex situation exists and more experimentation, particularly biochemical analysis, will be necessary to arrive at the proper causative factors. A new formula is presented for a chemically defined medium for Drosophila melanogaster, and detailed methods of preparation given. The new formula will support an estimated 200 larvae through complete development to adult flies on 5 ml of medium. It is thought that the system utilizing the development of Drosophila melanogaster on chemically defined amino acid medium is a fundamental one for the experimental analysis of developing insect populations.

Download Full-text