We have performed a full numerical calculation of the Franz-Keldysh （FK） effect on magnetoexcitons in a bulk GaAs semiconductor. By employing an initial wlue method in combination with the application of a perfect m...We have performed a full numerical calculation of the Franz-Keldysh （FK） effect on magnetoexcitons in a bulk GaAs semiconductor. By employing an initial wlue method in combination with the application of a perfect matched layer, the numerical effort and storage size are dramatically reduced due to a significant reduction in both computed domain and number of base functions. In the absence of an electric field, the higher magnetoexcitonic peaks show distinct Fano lineshape due to the degeneracy with continuum states of the lower Landau levels. The magnetoexcitons that belong to the zeroth Landau level remain in bound states and lead to Lorentzian lineshape, because they are not degenerated with continuum states. In the presence of an electric field, the FK effect on each magnetoexcitonic resonance can be identified for high magnetic fields. However, for low magnetic fields, the FK oscillations dominate the spectrum structure in the vicinity of the bandgap edge and the magnetoexcitonic resonances dominate the spectrum structure of higher energies. In the moderate electric fields, the interplay of FK effect and magnetoexcitonic resonance leads to a complex and rich structure in the absorption spectrum.展开更多
In this paper we discuss the fundamental solution of the Keldysh type operator Lαu■ 2u x2 + y 2yu y2 + α u y1 , which is a basic mixed type operator different from the Tricomi operator. The fundamental solution of ...In this paper we discuss the fundamental solution of the Keldysh type operator Lαu■ 2u x2 + y 2yu y2 + α u y1 , which is a basic mixed type operator different from the Tricomi operator. The fundamental solution of the Keldysh type operator with α>-1/2 is obtained. It is shown that the fundamental solution for such an operator generally has stronger singularity than that for the Tricomi operator. Particularly, the fundamental solution of the Keldysh type operator with α<1/2 has to be defined by using the finite part of divergent integrals in the theory of distributions.展开更多
In present work studied the new boundary value problem for semi linear(Power-type nonlinearities)system equations of mixed hyperbolic-elliptic Keldysh type in the multivariate dimension with the changing time directio...In present work studied the new boundary value problem for semi linear(Power-type nonlinearities)system equations of mixed hyperbolic-elliptic Keldysh type in the multivariate dimension with the changing time direction.Considered problem and equation belongs to the modern level partial differential equations.Applying methods of functional analysis,topological methods,“ε”-regularizing.and continuation by the parameter at the same time with aid of a prior estimates,under assumptions conditions on coefficients of equations of system,the existence and uniqueness of generalized and regular solutions of a boundary problem are established in a weighted Sobolev's space.In this work one of main idea consists of show that the new boundary value problem which investigated in case of linear system equations can be well-posed when added nonlinear terms to this linear system equations,moreover in this case constructed new weithged spaces,the identity between of strong and weak solutions is established.展开更多
The tunneling ionization of methyl acetate in the laser intensity range of 4.8× 1013 W· cm－ 2 to 1.3× 1014 W· cm－ 2 was studied.The modified Keldysh parameter was calculated by the ab initio meth...The tunneling ionization of methyl acetate in the laser intensity range of 4.8× 1013 W· cm－ 2 to 1.3× 1014 W· cm－ 2 was studied.The modified Keldysh parameter was calculated by the ab initio method.The tunneling probability was calculated by the WKB method.When the laser intensity was larger than 1014 W· cm－ 2,methyl acetate mainly took tunneling ionization mechanism.When the laser intensity was lower than 1014 W· cm－ 2 multiphoton ionization occurred.展开更多
基金Project supported by the Major Program of the National Natural Science Foundation of China （Grant No 10390160）, and the National Natural Science Foundation of China （Grant No 30370420）.
文摘We have performed a full numerical calculation of the Franz-Keldysh （FK） effect on magnetoexcitons in a bulk GaAs semiconductor. By employing an initial wlue method in combination with the application of a perfect matched layer, the numerical effort and storage size are dramatically reduced due to a significant reduction in both computed domain and number of base functions. In the absence of an electric field, the higher magnetoexcitonic peaks show distinct Fano lineshape due to the degeneracy with continuum states of the lower Landau levels. The magnetoexcitons that belong to the zeroth Landau level remain in bound states and lead to Lorentzian lineshape, because they are not degenerated with continuum states. In the presence of an electric field, the FK effect on each magnetoexcitonic resonance can be identified for high magnetic fields. However, for low magnetic fields, the FK oscillations dominate the spectrum structure in the vicinity of the bandgap edge and the magnetoexcitonic resonances dominate the spectrum structure of higher energies. In the moderate electric fields, the interplay of FK effect and magnetoexcitonic resonance leads to a complex and rich structure in the absorption spectrum.
基金supported by the National Basic Research Program of China (Grant No.2006CB805902)National Natural Science Foundation of China (Grant No.10531020)the Research Foundation for Doctor Programme (Grant No.20050246001)
文摘In this paper we discuss the fundamental solution of the Keldysh type operator Lαu■ 2u x2 + y 2yu y2 + α u y1 , which is a basic mixed type operator different from the Tricomi operator. The fundamental solution of the Keldysh type operator with α>-1/2 is obtained. It is shown that the fundamental solution for such an operator generally has stronger singularity than that for the Tricomi operator. Particularly, the fundamental solution of the Keldysh type operator with α<1/2 has to be defined by using the finite part of divergent integrals in the theory of distributions.
文摘In present work studied the new boundary value problem for semi linear(Power-type nonlinearities)system equations of mixed hyperbolic-elliptic Keldysh type in the multivariate dimension with the changing time direction.Considered problem and equation belongs to the modern level partial differential equations.Applying methods of functional analysis,topological methods,“ε”-regularizing.and continuation by the parameter at the same time with aid of a prior estimates,under assumptions conditions on coefficients of equations of system,the existence and uniqueness of generalized and regular solutions of a boundary problem are established in a weighted Sobolev's space.In this work one of main idea consists of show that the new boundary value problem which investigated in case of linear system equations can be well-posed when added nonlinear terms to this linear system equations,moreover in this case constructed new weithged spaces,the identity between of strong and weak solutions is established.
文摘The tunneling ionization of methyl acetate in the laser intensity range of 4.8× 1013 W· cm－ 2 to 1.3× 1014 W· cm－ 2 was studied.The modified Keldysh parameter was calculated by the ab initio method.The tunneling probability was calculated by the WKB method.When the laser intensity was larger than 1014 W· cm－ 2,methyl acetate mainly took tunneling ionization mechanism.When the laser intensity was lower than 1014 W· cm－ 2 multiphoton ionization occurred.
