24 research outputs found

    Quantum Diagonalization Method in the Tavis-Cummings Model

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    To obtain the explicit form of evolution operator in the Tavis-Cummings model we must calculate the term e−itg(S+⊗a+S−⊗a†){e}^{-itg(S_{+}\otimes a+S_{-}\otimes a^{\dagger})} explicitly which is very hard. In this paper we try to make the quantum matrix A≡S+⊗a+S−⊗a†A\equiv S_{+}\otimes a+S_{-}\otimes a^{\dagger} diagonal to calculate e−itgA{e}^{-itgA} and, moreover, to know a deep structure of the model. For the case of one, two and three atoms we give such a diagonalization which is first nontrivial examples as far as we know, and reproduce the calculations of e−itgA{e}^{-itgA} given in quant-ph/0404034. We also give a hint to an application to a noncommutative differential geometry. However, a quantum diagonalization is not unique and is affected by some ambiguity arising from the noncommutativity of operators in quantum physics. Our method may open a new point of view in Mathematical Physics or Quantum Physics.Comment: Latex files, 21 pages; minor changes. To appear in International Journal of Geometric Methods in Modern Physic

    Early Treatment with Methylprednisolone Pulse Therapy Combined with Tonsillectomy for Heavy Proteinuric Henoch-Schönlein Purpura Nephritis in Children

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    Background: There is no clear consensus as to which patients with Henoch-Schönlein purpura nephritis (HSPN) at risk of a poor outcome should be treated and what therapeutic regimen should be used. Methods: Nine children with heavy proteinuric HSPN received prompt initiation of methylprednisolone pulse therapy (MPT) combined with tonsillectomy in a prospective study. Results: At presentation, the mean values for the patients’ urine protein excretion (early-morning urinary protein/creatinine ratio), serum IgA, activity index (AI), and chronicity index (CI) were 5.0 ± 5.6 g/g Cr, 135.6 ± 56.5 mg/dl, 4.0 ± 0.7, and 1.7 ± 1.3, respectively. At the second biopsy, conducted approximately 24 months after initiation of therapy, the patients’ serum albumin had significantly increased (4.4 ± 0.2, p Conclusions: Early treatment with MPT combined with tonsillectomy is effective in ameliorating the histopathological progression and improving the clinical course of children with heavy proteinuric HSPN

    Explicit Form of the Evolution Operator of Tavis-Cummings Model : Three and Four Atoms Cases

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    In this letter the explicit form of evolution operator of the Tavis-Cummings model with three and four atoms is given. This is an important progress in quantum optics or mathematical physics.Comment: Latex file, 10 pages. We combined quant-ph/0404034(the three atoms case) and quant-ph/0406184(the four atoms case) into an article. to appear in International Journal of Geometric Methods in Modern Physic

    Cavity QED and Quantum Computation in the Weak Coupling Regime

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    In this paper we consider a model of quantum computation based on n atoms of laser-cooled and trapped linearly in a cavity and realize it as the n atoms Tavis-Cummings Hamiltonian interacting with n external (laser) fields. We solve the Schr{\" o}dinger equation of the model in the case of n=2 and construct the controlled NOT gate by making use of a resonance condition and rotating wave approximation associated to it. Our method is not heuristic but completely mathematical, and the significant feature is a consistent use of Rabi oscillations. We also present an idea of the construction of three controlled NOT gates in the case of n=3 which gives the controlled-controlled NOT gate.Comment: Latex file, 22 pages, revised version. To appear in Journal of Optics B : Quantum and Semiclassical Optic
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