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1.
We consider the usual Jaynes–Cummings model (JCM), in the presence of an external classical field. Under a certain canonical transformation for the Pauli operators, the system is transformed into the usual JCM. Using the equations of motion in the Heisenberg picture, exact solutions for the time-dependent dynamical operators are obtained. In order to calculate the expectation values of these operators, the wave function has been constructed. It has been shown that the classical field augments the atomic frequency ω0 and mixes the original atomic states. Changes of squeezing from one quadrature to another is also observed for a strong value of the coupling parameter of the classical field. Furthermore, the system in this case displays partial entanglement and the state of the field losses its purity. 相似文献
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《Physics letters. A》2020,384(14):126287
Time evolution of pertinent operators in the Rabi Hamiltonian and its rotating wave approximation (RWA) version, the Jaynes-Cummings model (JCM), in the Heisenberg picture, gives systems of nonlinear differential equations (NDEs). Considering well localized atom, the mean field theory (MFT) was applied to replace the operators by equivalent expectation values. The Rabi model was reduced to a fourth orders NDE describing atoms position. Solution by the harmonic balance method (HBM) showed good accuracy and consistency to the numerical results, which introduces it as a useful tool in the quantum dynamics studies. The NDEs describing the JCM in the Heisenberg picture structurally prevent applying the MFT and shows inconsistency to the Ehrenfest's theorem, contrary to the Rabi model. 相似文献
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本引入谐振子产生算符和湮没算符的逆算符,导出它们在Fock空间的表达式,并给出了一些简单应用。 相似文献
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R. D. Khan Zhang Jialun Ding Sheng Shen Wenda 《International Journal of Theoretical Physics》1993,32(11):2023-2029
The exact solution to a velocity-dependent quantum forced anharmonic oscillator is derived by using integral operators and an iteration method. The study is carried out in operational form by use of the creation and annihilation operators of the oscillator. The time development of the displacement and momentum operators of the anharmonic oscillator is given. These operators are presented as a Laplace transform and a subsequent inverse Laplace transform of suitable functionals. 相似文献
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利用玻色振子的逆算符构造了SU(1,1)群的生成元和不可约表示的相干态,导出了SU(1,1)群的非齐次逆微分实现. 相似文献
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The problem of variational data assimilation for a nonlinear evolution model is formulated as an optimal control problem to find unknown parameters such as distributed model coefficients or boundary conditions. The equation for the optimal solution error is derived through the errors of the input data (background and observation errors), and the optimal solution error covariance operator through the input data error covariance operators, respectively. The quasi-Newton BFGS algorithm is adapted to construct the covariance matrix of the optimal solution error using the inverse Hessian of an auxiliary data assimilation problem based on the tangent linear model constraints. Preconditioning is applied to reduce the number of iterations required by the BFGS algorithm to build a quasi-Newton approximation of the inverse Hessian. Numerical examples are presented for the one-dimensional convection–diffusion model. 相似文献
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Hong-Yi FAN 《理论物理通讯》1995,23(4):509-512
We construct q-deformed displaced number state, q-deformed twc-mode squeezed state and q-deformed two-mode single-complex-variable state by making use of the q-deformed inverse field operators. Their completeness relitions are investigated by virtue of the technique of integration within an ordered product of operators. Some new operator identities in q-deformed Fock space are also derived. 相似文献
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The generators and irreducible representation coherent state of the multimodeSU(2) group are constructed by using the inverse operators of the multimode bosonic harmonic oscillator, and the inhomogeneous
inverse differential realization of the multimodeSU(2) group are derived. 相似文献
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We have studied the effect of environment induced pure decoherence on the generalized Jaynes-Cummings model (JCM). This generalized
JCM is introduced to take into account both atom-field interaction and a class of spin-orbit interactions in the same framework.
For generalized JCM with atom-field interaction, it is shown that along with the suppression of the oscillatory behaviour
of the atomic and field variables, in the steady state, atomic energy is transferred to the field or vice versa through the
dressed state coherence depending on the initial condition of the atom-field system and the model under consideration. It
is also shown that initial Poissonian field acquires a sub-Poissonian character in the steady state and thus all the nonclassical
properties are not erased by the decoherence in JCM. An interesting effect of this decoherence mechanism is that it affects
the population and coherence properties of the individual subsystem in a different way. As an example of generalized JCM with
spin-orbit interaction, the dynamics of spin of the hydrogen atom in a magnetic field is studied to show the effect of decoherence. 相似文献
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An alternative approach to the Jaynes-Cummings model (JCM) with dissipation at a finite environmental temperature is presented in terms of a new master equation under Born-Markovian approximation. An analytic solution of the dissipation JCM is obtained. A variety ofphysical quantities of interest are calculated analytically. Dynamical properties of the atom and the field are investigated in some detail. It is shown that both cavity damping and environmental temperature strongly affect nonclassical effects in JCM, such as collapse and revivals of the atomic inversion, oscillations of the photon-number distribution, quadrature squeezing of the field and sub-Poissonian photon statistics. 相似文献
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F.A.A. El‐Orany 《Annalen der Physik》2008,17(6):424-432
In this paper we study the interaction between a two‐level atom and a quantized single‐mode field, namely, the Jaynes‐Cummings model (JCM). The field and the atom are initially prepared in the binomial state and the excited atomic state, respectively. For this system we prove that the revival‐collapse phenomenon exhibited in the atomic inversion of the standard JCM can be numerically (naturally) manifested in the evolution of the squeezing factor of the three‐photon (standard) JCM provided that the initial photon‐number distribution of the radiation field has a smooth envelope. 相似文献
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The generators and irreducible representationcoherent state of the two-parameter deformed(q,s-deformed) quasi-SU(2) group are constructed byusing the inverse q,s operators of the q,s-deformed bosonic oscillator, and the inhomogeneousinverse differential realization of the q,s-deformedquasi-SU(2)q,s group is derived. 相似文献
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Khalid Masood 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2006,82(7):224-231
We investigate the inverse problem associated with the heat equation involving recovery of initial temperature distribution in a two-layer cylinder with perfect thermal contact at the interface. The heat equation is solved backward in time to obtain a relationship between the final temperature distribution and the initial temperature profile. An integral representation for the problem is found, from which a formula for initial temperature is derived using Picard’s criterion and the singular system of the associated operators. The known final temperature profile can be used to recover the initial temperature distribution from the formula derived in this paper. A robust method to regularize the outcome by introducing a small parameter in the governing equation is also presented. It is demonstrated with the help of a numerical example that the hyperbolic model gives better results as compared to the parabolic heat conduction model. 相似文献
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Introducing the fermionic R-operator and solutions of the inverse scattering problem for local fermion operators, we derive a multiple integral representation for zero-temperature correlation functions of a one-dimensional interacting spinless fermion model. Correlation functions particularly considered are the one-particle Green's function and the density–density correlation function both for any interaction strength and for arbitrary particle densities. In particular for the free fermion model, our formulae reproduce the known exact results. Form factors of local fermion operators are also calculated for a finite system. 相似文献
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The bi-Hamiltonian structure of integrable supersymmetric extensions of the Korteweg-de Vries (KdV) equation related to theN=1 and theN=2 superconformal algebras is found. It turns out that some of these extensions admit inverse Hamiltonian formulations in terms of presymplectic operators rather than in terms of Poisson tensors. For one extension related to theN=2 case additional symmtries are found with bosonic parts that cannot be reduced to symmetries of the classical KdV. They can be explained by a factorization of the corresponding Lax operator. All the bi-Hamiltonian formulations are derived in a systematic way from the Lax operators. 相似文献
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L. Martínez Alonso 《Letters in Mathematical Physics》1984,8(2):111-117
The quantum nonlinear Schrödinger equation with attractive coupling is considered through the quantum inverse scattering method. The asymptotic fields arising in this model are characterized in terms of scattering data operators. 相似文献