In this article, the coupling equations of the laser, the first Stokes, the first anti-Stokes light, and the coherent phonon field are derived from the hamiltonian with the relaxation and dissipation terms introduced phenomenologically. The properties of these equations are analysed by adopting an approximation higher than the quasi-static approximation, provided the molecules are far from resonance. The threshold for a Raman Maser is obtained and the temporal behaviour discussed. It is shown that no additional threshold condition is required for the anti-Stokes components, i.e., the stimulated anti-Stokes radiations make their appearance as a matter of fact in the stimulated Raman effect. Under certain conditions, there exists only one stable equilibrium point, at which the Stokes and anti-Stokes light appear with equal intensity, when the Raman-active medium is pumped by an intensive laser beam. The effect of phonon relaxation and the behaviour of the Raman Maser with long lifetime phonons are discussed as well.
In this article, the coupling equations of the laser, the first Stokes, the first anti-Stokes light, and the coherent phonon field are derived from the hamiltonian with the relaxation and dissipation terms introduced phenomenologically. The properties of these equations are analysed by adopting an approximation higher than the quasi-static approximation, provided the molecules are far from resonance. The threshold for a Raman Maser is obtained and the temporal behaviour discussed. It is shown that no additional threshold condition is required for the anti-Stokes components, i.e., the stimulated anti-Stokes radiations make their appearance as a matter of fact in the stimulated Raman effect. Under certain conditions, there exists only one stable equilibrium point, at which the Stokes and anti-Stokes light appear with equal intensity, when the Raman-active medium is pumped by an intensive laser beam. The effect of phonon relaxation and the behaviour of the Raman Maser with long lifetime phonons are discussed as well.
A new representation of (real and virtual) localized modes in the solid state problems is formulated by considering P(z), the modified resolvent operator. It has singularities on the real axis of the z plane only. The isolated poles correspond to real localized modes. When P(E+iη) is analytically continuated onto the second Riemann surface (η > 0), its complex poles correspond to virtual (or unstable) localized modes. The real part of the complex pole is the energy of an unstable localized mode, and the reciprocal of the imaginary part is its life-time. Naturally the life-time is positive. The energy and life-time derived in this way are in accordance with the energy and width of the corresponding resonance scattering. The relation between real and virtual localized modes is discussed. Finally, the singularities of P(z) are related with the change in density of state. The differences between solutions with positive life-times and that with negative life-times are further explained. It is pointed out that, in general, only solutions with positive life-times can change into localized modes when the interaction strength increases, while for solutions with a negative life-time this does not happen.
A new representation of (real and virtual) localized modes in the solid state problems is formulated by considering P(z), the modified resolvent operator. It has singularities on the real axis of the z plane only. The isolated poles correspond to real localized modes. When P(E+iη) is analytically continuated onto the second Riemann surface (η > 0), its complex poles correspond to virtual (or unstable) localized modes. The real part of the complex pole is the energy of an unstable localized mode, and the reciprocal of the imaginary part is its life-time. Naturally the life-time is positive. The energy and life-time derived in this way are in accordance with the energy and width of the corresponding resonance scattering. The relation between real and virtual localized modes is discussed. Finally, the singularities of P(z) are related with the change in density of state. The differences between solutions with positive life-times and that with negative life-times are further explained. It is pointed out that, in general, only solutions with positive life-times can change into localized modes when the interaction strength increases, while for solutions with a negative life-time this does not happen.
By utilizing the LT representation and considering the effect of spin-spin interaction in the d3 configuration, the authors calculated the zero-field splitting of ground state in ruby and obtained a result of 2D =-0.12 cm-1 for the zero-field splitting.
By utilizing the LT representation and considering the effect of spin-spin interaction in the d3 configuration, the authors calculated the zero-field splitting of ground state in ruby and obtained a result of 2D =-0.12 cm-1 for the zero-field splitting.
The chemical etching method is used to reveal dislocations produced by indentation on silicon single crystal specimens. Edge (or 60°) dislocation velocities are measured under different shear stresses and at different temperatures (700-900℃). By assuming that the motion is thermally activated, the corresponding activation energy is obtained to be ～2.94 eV. Velocities of edge (or 60°) dislocations and screw dislocations at 900℃ are compared, the latter being smaller. Measurements of dislocation velocities on different specimens show the retarding effect of as-grown dislocations. Dislocation multiplication is observed from as-grown dislocations and from grain boundaries. Dislocation velocities in process of multiplication are measured. Factors affecting the measured values of dislocation velocities are discussed.
The chemical etching method is used to reveal dislocations produced by indentation on silicon single crystal specimens. Edge (or 60°) dislocation velocities are measured under different shear stresses and at different temperatures (700-900℃). By assuming that the motion is thermally activated, the corresponding activation energy is obtained to be ～2.94 eV. Velocities of edge (or 60°) dislocations and screw dislocations at 900℃ are compared, the latter being smaller. Measurements of dislocation velocities on different specimens show the retarding effect of as-grown dislocations. Dislocation multiplication is observed from as-grown dislocations and from grain boundaries. Dislocation velocities in process of multiplication are measured. Factors affecting the measured values of dislocation velocities are discussed.
In this paper the induced uniaxial magnetic anisotropy of ferrites containing Co2+ and Ni2+ is discussed. For the former case, it starts from the mechanism proposed by Iida, taking into account the influence of cation vacancy upon the energy levels and wave functions of Co2+; while for the latter case, it is based upon the mechanism introduced by Schnettler-Gyorgy, considering the Jahn-Teller effect of Ni2+ in tetrahedral sites and deriving its energy levels and wave functions. Then the induced uniaxial magnetic anisotropy of both materials is calculated and may be comparable with the experimental results. The mechanism of the deviation of θu with θα is also discussed.
In this paper the induced uniaxial magnetic anisotropy of ferrites containing Co2+ and Ni2+ is discussed. For the former case, it starts from the mechanism proposed by Iida, taking into account the influence of cation vacancy upon the energy levels and wave functions of Co2+; while for the latter case, it is based upon the mechanism introduced by Schnettler-Gyorgy, considering the Jahn-Teller effect of Ni2+ in tetrahedral sites and deriving its energy levels and wave functions. Then the induced uniaxial magnetic anisotropy of both materials is calculated and may be comparable with the experimental results. The mechanism of the deviation of θu with θα is also discussed.
It is assumed that the vector meson φ is a resonance which is formed of the KK scattering by exchange of ρ, ω and φ itself. The method of N/D of the double dispersion relation is used and the experimental values of the masses are known for the ρ, ω and exchanged φ. The partial wave amplitude of the KK scattering is given approximately. When it is required for the partial wave amplitude to give in turn the correct position and width of the resonance, the relations for the coupling constants fφKK2,fωKK2 and fρKK2 are found and the values available for them are determined.
It is assumed that the vector meson φ is a resonance which is formed of the KK scattering by exchange of ρ, ω and φ itself. The method of N/D of the double dispersion relation is used and the experimental values of the masses are known for the ρ, ω and exchanged φ. The partial wave amplitude of the KK scattering is given approximately. When it is required for the partial wave amplitude to give in turn the correct position and width of the resonance, the relations for the coupling constants fφKK2,fωKK2 and fρKK2 are found and the values available for them are determined.
In this paper, the general form of the Regge representation of the scattering amplitude has been established as where Pl(μ,ν)(z) is the Jacobi function. The relationship between such a representation and the usual Regge representation has been studied in detail. Some properties of the Jacobi functions are discussed in the appendix.
In this paper, the general form of the Regge representation of the scattering amplitude has been established as where Pl(μ,ν)(z) is the Jacobi function. The relationship between such a representation and the usual Regge representation has been studied in detail. Some properties of the Jacobi functions are discussed in the appendix.
Energy levels corresponding to ligand field transition bands of complex ions CuX4-(X = Cl, Br) were given. The quantitative relation between positions of absorption bands and structures of these complex ions was deduced. Calculation results agree with experimental findings.
Energy levels corresponding to ligand field transition bands of complex ions CuX4-(X = Cl, Br) were given. The quantitative relation between positions of absorption bands and structures of these complex ions was deduced. Calculation results agree with experimental findings.