The quantum solitary wave solutions in a one-dimensional ferromagnetic chain is investigated by using theHartree-Fock approach and the multiple-scale method.It is shown that quantum solitary wave solutions can exist i...The quantum solitary wave solutions in a one-dimensional ferromagnetic chain is investigated by using theHartree-Fock approach and the multiple-scale method.It is shown that quantum solitary wave solutions can exist in aferromagnetic system with nearest-and next-nearest-neighbor exchange interaction,and at the certain value of the firstBrillouin zone,the solitary wave solution of the Hartree wave function becomes the intrinsic localized mode.展开更多
The electron-phonon interaction influences on lineax and nonfineax optical absorption in cylindrical quantum wires (CQW) with an infinite confining potential axe investigated. The optical absorption coefficients are...The electron-phonon interaction influences on lineax and nonfineax optical absorption in cylindrical quantum wires (CQW) with an infinite confining potential axe investigated. The optical absorption coefficients are obtained by using the compact-density-matrix approach and iterative method, and the numerical results are presented for GaAs CQW. The results show that the electron-phonon interaction makes a distinct influence on optical absorption in CQW. The electron-phonon interaction on the wave functions of electron dominates the values of absorption coefficients and the correction of the electron-phonon effect on the energies of the electron makes the absorption peaks blue shift and become wider. Moreover, the electron-phonon interaction influence on optical absorption with an infinite confining potential is different from that with a finite confining potential.展开更多
We calculate the energy levels of low-lying states of a two-electron quantum ring under the influence of perpendicular homogeneous magnetic field. Calculations are made by using the method of exact diagonalization wit...We calculate the energy levels of low-lying states of a two-electron quantum ring under the influence of perpendicular homogeneous magnetic field. Calculations are made by using the method of exact diagonalization within the effective-mass approximation. The ground-state electronic structures and angular momentum transitions as a function of the strength of a magnetic field have been revealed.展开更多
With a weak hyperon-hyperon (YY) interaction deduced from the new experimental data of AA potential, this paper has performed a calculation of the direct Urca (DURCA) processes in the framework of the relativistic...With a weak hyperon-hyperon (YY) interaction deduced from the new experimental data of AA potential, this paper has performed a calculation of the direct Urca (DURCA) processes in the framework of the relativistic mean field theory (RMFT) including σ* and φ mesons, in comparison with the results calculated with the strong YY interaction and with no (σ* ,φ ) mesons included. In neutron star matter, the weak YY interaction supplies the additional repulsive interaction between hyperons while the strong YY interaction supplies the attractive one. With the weak YY interaction, the effective masses of hyperons are larger than those with the strong YY interaction while smaller than those with no (σ* ,φ) mesons included. The threshold star masses for the DURCA processes involving nucleons and A are not sensitive to the strength of the YY interaction. The weak YY interaction leads to larger threshold masses for the DURCA process involving [1]1 and [1]0 than the other two cases. The process involving [1]0 can take place in the neutron star only when the weak YY interaction is used. The weak YY interaction is able to bring in the agreement with the observation of the neutron star with larger mass and faster cooling than the strong YY interaction.展开更多
The transmission of quantum states in the anisotropic Heisenberg XXZ chain model with three-spin exchange interaction is studied. The average fidelity is used to evaluate the state transfer. It is found that quantum c...The transmission of quantum states in the anisotropic Heisenberg XXZ chain model with three-spin exchange interaction is studied. The average fidelity is used to evaluate the state transfer. It is found that quantum communication can be enhanced by the anisotropic coupling and multiple spin interaction. Such spin model can reduce the time required for the perfect state transmission where the fidelity is unity. The maximally entangled Bell states can be generated and separated from the whole quantum systems.展开更多
It is well known that energy-momentum is the source of gravitational field. For a long time, it is generally believed that only stars with huge masses can generate strong gravitational field. Based on the unified theo...It is well known that energy-momentum is the source of gravitational field. For a long time, it is generally believed that only stars with huge masses can generate strong gravitational field. Based on the unified theory of gravitational interactions and electromagnetic interactions, a new mechanism of the generation of gravitational field is studied. According to this mechanism, in some special conditions, electromagnetic energy can be directly converted into gravitational energy, and strong gravitational field can be generated without massive stars. Gravity impulse found in experiments is generated by this mechanism.展开更多
In quantum gauge theory of gravity, the gravitational field is represented by gravitational gauge field.The field strength of gravitational gauge field has both gravitoelectric component and gravitomagnetic component....In quantum gauge theory of gravity, the gravitational field is represented by gravitational gauge field.The field strength of gravitational gauge field has both gravitoelectric component and gravitomagnetic component. In classical level, gauge theory of gravity gives classical Newtonian gravitational interactions in a relativistic form. Besides,it gives gravitational Lorentz force, which is the gravitational force on a moving object in gravitomagnetic field The direction of gravitational Lorentz force is not the same as that of classical gravitational Newtonian force. Effects of gravitational Lorentz force should be detectable, and these effects can be used to discriminate gravitomagnetic field from ordinary electromagnetic magnetic field.展开更多
With the values of parameters obtained from improved ligand-field theory,by taking into account all theirreducible representations and their components in EPI as well as all the levels and the admixtures of basic wave...With the values of parameters obtained from improved ligand-field theory,by taking into account all theirreducible representations and their components in EPI as well as all the levels and the admixtures of basic wavefunc-tions within d^3 electronic configuration,the R-line thermal broadenings(TB)of both MgO:Cr^(3+)and MgO:V^(2+)havemicroscopic-theoretically been calculated.The results are in very good agreement with the experimental data.It is foundthat the R-line TB of MgO:Cr^(3+)or MgO:V^(2+)comes from the first-order term of EPI.The elastic Raman scattering ofacoustic phonons plays a dominant role in R-line TB of MgO:Cr^(3+)or MgO:V^(2+).展开更多
In this paper we present a general theoretical model for the interaction between a number of two-level atoms constituting Bose-Einstein condensate (BEG) and a single-mode quantized field. In addition to the usual in...In this paper we present a general theoretical model for the interaction between a number of two-level atoms constituting Bose-Einstein condensate (BEG) and a single-mode quantized field. In addition to the usual interacting terms, we take into account interatom as well as higher-order atom-field interactions. To simplify the Hamiltonian of system, after using the Bogoliubov approximation we proceed to calculate the transformed operators of atoms and field. Then, to quantify the spontaneous emission, we get analytical expressions for the expectation value of Jz as the atomic population inversion (API), in the cases of number and coherent states for the atomic subsystem. Our results show that the above-mentioned model interaction leads to the appearance of collapse-revival phenomenon in API. In more detail, the revival time may be tuned by adjusting the interatom interaction constant. Also, the damping process lowers the amplitude of API, but does not change the CR times for weak damping. Moreover, increasing the damping may decrease the number of CRs in a given interval of time such that no revival occurs. Briefly, it may be concluded that in the resonant case the revival times are insensitive to the change of the higher-order atom-field interaction constant and are affected only by the interatom interactions. Finally, we express that, how we can find a practical procedure to measure the quantum states of atoms in BEG.展开更多
基金supported by the Natural Science Foundation of Education Department of Hunan Province under Grant Nos.06C652 and 07C528National Natural Science Foundation of China under Grant No.10647132
文摘The quantum solitary wave solutions in a one-dimensional ferromagnetic chain is investigated by using theHartree-Fock approach and the multiple-scale method.It is shown that quantum solitary wave solutions can exist in aferromagnetic system with nearest-and next-nearest-neighbor exchange interaction,and at the certain value of the firstBrillouin zone,the solitary wave solution of the Hartree wave function becomes the intrinsic localized mode.
基金Scientific Research Fired of the Education Department of Zhejiang Province of China
文摘The electron-phonon interaction influences on lineax and nonfineax optical absorption in cylindrical quantum wires (CQW) with an infinite confining potential axe investigated. The optical absorption coefficients are obtained by using the compact-density-matrix approach and iterative method, and the numerical results are presented for GaAs CQW. The results show that the electron-phonon interaction makes a distinct influence on optical absorption in CQW. The electron-phonon interaction on the wave functions of electron dominates the values of absorption coefficients and the correction of the electron-phonon effect on the energies of the electron makes the absorption peaks blue shift and become wider. Moreover, the electron-phonon interaction influence on optical absorption with an infinite confining potential is different from that with a finite confining potential.
基金National Natural Science Foundation of China under Grant No.10475021
文摘We calculate the energy levels of low-lying states of a two-electron quantum ring under the influence of perpendicular homogeneous magnetic field. Calculations are made by using the method of exact diagonalization within the effective-mass approximation. The ground-state electronic structures and angular momentum transitions as a function of the strength of a magnetic field have been revealed.
基金Supported by the Natural Science Fundamental Research Project of Jiangsu Colleges and Universities under Grant No.10KJB140002
文摘With a weak hyperon-hyperon (YY) interaction deduced from the new experimental data of AA potential, this paper has performed a calculation of the direct Urca (DURCA) processes in the framework of the relativistic mean field theory (RMFT) including σ* and φ mesons, in comparison with the results calculated with the strong YY interaction and with no (σ* ,φ ) mesons included. In neutron star matter, the weak YY interaction supplies the additional repulsive interaction between hyperons while the strong YY interaction supplies the attractive one. With the weak YY interaction, the effective masses of hyperons are larger than those with the strong YY interaction while smaller than those with no (σ* ,φ) mesons included. The threshold star masses for the DURCA processes involving nucleons and A are not sensitive to the strength of the YY interaction. The weak YY interaction leads to larger threshold masses for the DURCA process involving [1]1 and [1]0 than the other two cases. The process involving [1]0 can take place in the neutron star only when the weak YY interaction is used. The weak YY interaction is able to bring in the agreement with the observation of the neutron star with larger mass and faster cooling than the strong YY interaction.
基金Supported by the Research Program of Natural Science for Colleges and Universities in Jiangsu Province under Grant No.09KJB140009the National Natural Science Foundation under Grant No.10904104
文摘The transmission of quantum states in the anisotropic Heisenberg XXZ chain model with three-spin exchange interaction is studied. The average fidelity is used to evaluate the state transfer. It is found that quantum communication can be enhanced by the anisotropic coupling and multiple spin interaction. Such spin model can reduce the time required for the perfect state transmission where the fidelity is unity. The maximally entangled Bell states can be generated and separated from the whole quantum systems.
文摘It is well known that energy-momentum is the source of gravitational field. For a long time, it is generally believed that only stars with huge masses can generate strong gravitational field. Based on the unified theory of gravitational interactions and electromagnetic interactions, a new mechanism of the generation of gravitational field is studied. According to this mechanism, in some special conditions, electromagnetic energy can be directly converted into gravitational energy, and strong gravitational field can be generated without massive stars. Gravity impulse found in experiments is generated by this mechanism.
文摘In quantum gauge theory of gravity, the gravitational field is represented by gravitational gauge field.The field strength of gravitational gauge field has both gravitoelectric component and gravitomagnetic component. In classical level, gauge theory of gravity gives classical Newtonian gravitational interactions in a relativistic form. Besides,it gives gravitational Lorentz force, which is the gravitational force on a moving object in gravitomagnetic field The direction of gravitational Lorentz force is not the same as that of classical gravitational Newtonian force. Effects of gravitational Lorentz force should be detectable, and these effects can be used to discriminate gravitomagnetic field from ordinary electromagnetic magnetic field.
基金supported partially by National Natural Science Foundation of China under Grant No.40841012
文摘With the values of parameters obtained from improved ligand-field theory,by taking into account all theirreducible representations and their components in EPI as well as all the levels and the admixtures of basic wavefunc-tions within d^3 electronic configuration,the R-line thermal broadenings(TB)of both MgO:Cr^(3+)and MgO:V^(2+)havemicroscopic-theoretically been calculated.The results are in very good agreement with the experimental data.It is foundthat the R-line TB of MgO:Cr^(3+)or MgO:V^(2+)comes from the first-order term of EPI.The elastic Raman scattering ofacoustic phonons plays a dominant role in R-line TB of MgO:Cr^(3+)or MgO:V^(2+).
文摘In this paper we present a general theoretical model for the interaction between a number of two-level atoms constituting Bose-Einstein condensate (BEG) and a single-mode quantized field. In addition to the usual interacting terms, we take into account interatom as well as higher-order atom-field interactions. To simplify the Hamiltonian of system, after using the Bogoliubov approximation we proceed to calculate the transformed operators of atoms and field. Then, to quantify the spontaneous emission, we get analytical expressions for the expectation value of Jz as the atomic population inversion (API), in the cases of number and coherent states for the atomic subsystem. Our results show that the above-mentioned model interaction leads to the appearance of collapse-revival phenomenon in API. In more detail, the revival time may be tuned by adjusting the interatom interaction constant. Also, the damping process lowers the amplitude of API, but does not change the CR times for weak damping. Moreover, increasing the damping may decrease the number of CRs in a given interval of time such that no revival occurs. Briefly, it may be concluded that in the resonant case the revival times are insensitive to the change of the higher-order atom-field interaction constant and are affected only by the interatom interactions. Finally, we express that, how we can find a practical procedure to measure the quantum states of atoms in BEG.