1991年, 第15卷, 第4期　
刊出日期：1991-06-15

  

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  Cyclotron Resonance of a Magnetopolaron in a Quantum Well at Finite Temperatures

  Baohua WEI, Shiwei GU

  理论物理通讯. 1991, 15(4): 385-394.

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  Taking into account the interaction of an electron with both bulk longitudinal-optical (BO) and surface-optical (SO) phonons, the cyclotron resonance of a magnetopolaron in a quantum well at finite temperatures is investigated by using the generalized Larsen perturbationtheory method. It is shown that the absorption and emission resonances must be considered at the same time at finite temperatures. The results also show that the electron-SO phonon interaction plays an important role as well as the electron-BO phonon interaction, especially when the quantum well width is getting thinner. For an experimentally interesting GaAs/Ga_1-xAl_xAs sandwich structure, the splitting of the cyclotron resonance spectrum and the temperature dependence of two splitting cyclotron resonance mass of the magnetopolaron in the resonant magnetic field region have been studied.
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  Two-δ- Function Generalized Plasma Pole Model for First Principle Calculations of Quasiparticle Energies in Many-Electron Systems

  WANG Jianqing, GU Zongquan, LI Mingfu

  理论物理通讯. 1991, 15(4): 395-402.

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  To evaluate the dynamical effects of the screened interaction in the calculations of quasiparticle energies in many-electron systems a two-δ-function generalized plasma pole model (GPP) is introduced to simulate the dynamical dielectric function. The usual single δ-function GPP model has the drawback of over simplifications and for the crystals without.the center of symmetry is inappropriate to describe the finite frequency behavior for dielectric function matrices. The discrete frequency summation method requires too much computation to achieve converged results since ab initio calculations of dielectric function matrices are to be carried out for many different frequencies. The two-δ GPP model is an op timization of the two approaches. We analyze the two-δ GPP model and propose a method to determine from the first principle calculations the amplitudes and effective frequencies of these δ functions. Analytical solutions are found for the second order equations for the parameter matrices entering the model. This enables realistic applications of the method to the first principle quasiparticle calculations and makes the calculations truly adjustable parameter free.
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  Vibrational Modes of Photo-Excited in Quasi-One-Dimensional Halogen- Bridged Mixed-Valence Compounds

  PENG Jingcui, PENG Jian

  理论物理通讯. 1991, 15(4): 403-410.

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  Vibrational modes of photo-excited in quasi-one-dimensional halogen-bridged mixedvalence compounds are investigated by using tight-binding model for electrons and quasiharmonic approximation for lattice vibration. Pt-halogen compound is taken as a onedimensional two-atom base chain, and the unit cell contains 12 atoms and a 12×12 dynamical matrix D_ij follows. Solving the corresponding determinantal equation numerically, the 12 eigenfrequencies are found. They are more accurate than the ones by harmonic approximation in comparison with the experimental data.
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  On the Hidden Symmetry Algebras of the Classical Principal Chiral Model

  LU jingfa, CHAO Liu

  理论物理通讯. 1991, 15(4): 411-420.

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  The hidden symmetries of the principal chiral model are studied by using the new infinitesimal Riemann-Hilbert transformations. It is found that the algebra of hidden symmetries decomposes into the semidirect sum of the loop algebra and the conformal algebra of the plane, where both subalgebras are Lie multi-algebras with each Lie product being a Baxter-Lie product with respect to some special solution of the modified classical Yang-Baxter equation. Two special examples of the Lie products are given, which are consistent with Wu's, Avan and Bellon's results.
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  Explicit N-Soliton Solution of the Modified Nonlinear SchrSdinger Equation by Means of the Inverse Scattering Transformation

  Zongyun CHEN

  理论物理通讯. 1991, 15(4): 421-426.

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  The Zakharov-Shabat equations o: inverse scattering transformation for the modified nonlinear Schr6dinger equation in the reflectionless case are solved by means of the technique of determinant calculation. An explicit expression of the N-soliton solution is obtained. Its expected asymptotic behavior is derived.
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  Non-Abelian Induced Topological Action for Slowly Changing Quantum System and Non-Adiabatic Corrections

  Changpu SUN, Lei WANG, Molin GE

  理论物理通讯. 1991, 15(4): 427-436.

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  The induced topological action relevant to the non-Abelian Berry's phase factor (NABPF) is derived by combining the high-order adiabatic approximation (HOAA) method with Kuratsuji and Iida's adiabatic path integral formulation. The non-adiabatic corrections for the transition amplitude are thereby obtained and the corresponding graphic representations are defined for convenience in the calculation. The gauge invariant properties and the dynamical implications of the non-Abelian induced topological action are also analyzed in detail.Finally, some explicit calculations for a model of physics are carried out as examples.
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  Exact Three-Dimensional Relativistic Equation for qq Bound states

  SU Junchen, MU Desheng

  理论物理通讯. 1991, 15(4): 437-450.

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  Starting with the QCD generating functional, a new derivation and a new form of the Dirac-Schriidinger (D-S) equation,catisfied by the equal-time Bethe-Salpeter amplitude of quark-antiquark bound states have been given. In this equation, the effective interaction kernel has a compact expression and can be directly calculated by means of the conventional QCD Feynman rules. F'urthermore, an equivalent reduction of the above equation to a Pauli-Schriidinger equation has also been achieved and a closed form of the effective interaction Hamiltonian appearing in the latter equation has been explicitly written out.
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  Bethe-Salpeter Equation with Self-Energy Graphs Ⅲ-Numerical Solution and the Abnormal State Problem

  CHENG Geng, LI Laiyu

  理论物理通讯. 1991, 15(4): 451-464.

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  Parameter imbedding method for nonlinear parameter integral equation developed in paper I is applied to the BS equation with self-energy graphs discussed in paper 11. Numerical algorithm and computer code are presented. An example problem, which can be treated analytically, is run on the computer VAX-8700 in the USTC, China. The numerical results are excellent. The continuous spectrum and the discrete eigenvalues of the model problem are investigated attentively and calculated on nearly the whole closed complex plane by using the numerical code. Several sets of parameters p (the mass of the exchanged bosons) and μ(the bound energy of the bound state) are given. The numerical results exhibit some strong evidences, which make us come to the suggestion that there are no discrete abnormal states in all the cases we considered when the self-energy is included.
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  Some New Solutions of the KP Equation

  Senyue LOU

  理论物理通讯. 1991, 15(4): 465-472.

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  There exist three types of similarity reductions for the Kadomtsev-Petviaahvili equation. Various new solutions of the second and third types of the reductions are discussed in detail.Lots of arbitrary functions oft are included in these solutions.
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  Flute Instability in Tandem Mirror

  理论物理通讯. 1991, 15(4): 473-480.

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  The flute instability of low β，inhomogeneous, uniformly rotating plasma with emphasis on application to central cell plasma of TM machine is discussed. The analytical solvabta model studied in this work provides more comprehensive information than previous works by using a similar model. The conducting wall effect on the m=1 mode is considered. Application to density fluctuation observed in the central cell of GAMMA 10 and TMX shows a fairly good agreement between experiment and theory.
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  Theory of Shear Alfven Vortex in Current-Carrying Plasma Plasma

  Yinhua CHEN, Jixing LIU

  理论物理通讯. 1991, 15(4): 481-488.

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  Nonlinear shear Alfven waves in low P, current-carrying magnetized plasma are studied.Sets of nonlinear equations describing the shear Alfven waves are derived and corresponding dipolar vortex solutions are given for both regions of P, 0<β< m_e/m_i and m_e/m_i<<β<<1, respectively. Result shows that the equilibrium plasma current has remarkable effect on the behaviour of vortex motion. For the 0<β<< m_e/m_i case the current adds a low speed vortex propagating region in the opposite current direction, while for the < m_e/m_i<<β<<1 case the current reduces the region of vortex propagating speed by cutting a low speed region. The implication of this effect is discussed.
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  Quasiperiodic Solutions of Some Nonlinear Schrödinger Equations with Optical solitons

  Yi XIAO

  理论物理通讯. 1991, 15(4): 489-492.

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  Quasiperiodic solutions of the derivative nonlinear Schriidinger equation, the modified nonlinear Schriidinger equation and the coupled nonlinear Schriidinger equations are found by ueing the BHcklund transformations.
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  The Exact Large Amplitude Circular Polarized Plane Wavelin a Ferromagnetic System Under a Bias Magnetic Field

  Ying WU, Xiaoxue YANG

  理论物理通讯. 1991, 15(4): 493-496.

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  The exact nonlinear dispersion relation for circular polarized plane wave propagating along magnetic field in a ferromagnetic system is derived. It is pointed out that the right polarized wave can be modulationally unstable and may evolve into a soliton.
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  The Kondo Problem as the Quantum Sine-Gordon Model

  Guangming ZHANG, Hong CHEN, Xiang WU

  理论物理通讯. 1991, 15(4): 497-500.

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  The ground-state properties of the Kondo Hamiltonian is analyzed in detail and we find the problem to be exactly equivalent to a modified quantum sine-Gordon model. Paralleling to the renormalization-group theory of the sine-Gordon model, we easily derive the correct next-to-leading order flow equations and obtain a universal quantity in a linear combination of the coefficients of the higher-order terms.
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  A Possible Origin of Cu-O Plane Buckling in YBa₂Cu₃O₇

  WU Hangsheng, LOU Ping

  理论物理通讯. 1991, 15(4): 501-504.

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  The magnetic contribution to the thermal expansion of Cu-O layer in YBa₂Cu₃O_7-6 is studied with the nearly antiferronagnet Ficermi liquid model. Our analysis suggests that this additional thermal expansion due to antiferromagnetic spin fluctuation is the origin of the Cu-O plane buckling.
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  Power Series Solutions for Vesicles

  Weimou ZHENG, Zhongcan OU-YANG

  理论物理通讯. 1991, 15(4): 505-508.

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  A procedure of seeking power series solutions ia proposed for vesicle models.
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  Gauge Anomaly in 'Arbitrary Even Dimensions from Stochastic Quantization

  ZHOU Jiange, DAI Qinghai, LIU Yaoyang

  理论物理通讯. 1991, 15(4): 509-512.

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  The stochastic quantization method is applied to evaluate gauge anomaly in arbitrary even dimensions. Stochastic regularization plays a distinct role in our method. The. anomaly structure of the anomalous model is studied.