The energy spectra of the ground state for an exciton (X) trapped by a neutral acceptor (A^o) in a quantumdot with a parabolic confinement have been calculated as a function of the electron-to-hole mass ratio σ by us...The energy spectra of the ground state for an exciton (X) trapped by a neutral acceptor (A^o) in a quantumdot with a parabolic confinement have been calculated as a function of the electron-to-hole mass ratio σ by using thehyperspherical coordinates. We find that the (A^o, X) complex confined in a quantum dot has in general a larger bindingenergy than those in a two-dimensional quantum well and a three-dimensional bulk semiconductor, and the bindingenergy decreases with the increase of the electron-to-hole mass ratio.展开更多
Two-electron states of a three-dimensional spherical GaAs quantum dot (QD) with a Gaussian confining potential confinement are studied. Calculations are made by using the method of few-body physics within the effectiv...Two-electron states of a three-dimensional spherical GaAs quantum dot (QD) with a Gaussian confining potential confinement are studied. Calculations are made by using the method of few-body physics within the effectivemass approximation. We have calculated the energy levels of single and triplet states as functions of the range and depth of the confining potential well in the spherical QDs. The same calculations performed with the parabolic approximation of the Gaussian potential lead to the results, which are qualitatively and quantitatively different.展开更多
We consider the problem of an electron-hole pair in a Gaussian confining potential well. This problem is treated within the effective-mass approximation framework using the method of numerical matrix diagonalization. ...We consider the problem of an electron-hole pair in a Gaussian confining potential well. This problem is treated within the effective-mass approximation framework using the method of numerical matrix diagonalization. The energy levels of the low-lying states are calculated as a function of the electron-hole effective mass ratio and the size of the confining potential.展开更多
Making use of hyperspherical coordinates, we investigate the qualitative features of the ground and lowlying states of a positronium molecule confined in a two-dimensional (2D) space under a magnetic field. We find th...Making use of hyperspherical coordinates, we investigate the qualitative features of the ground and lowlying states of a positronium molecule confined in a two-dimensional (2D) space under a magnetic field. We find that a positronium molecule has more bound states in 2D than in 3D. With the increase of the magnetic field, the second bound state experiences a transition in angular momentum. The result shows that symmetry plays an essential role in the energy spectrum of low-lying states.展开更多
The exciton L = 0 and L = 1 states of a spherical GaAs quantum dot with a Gaussian confining potential are calculated by using the matrix diagonalization method. The size dependence of the exciton levels and the influ...The exciton L = 0 and L = 1 states of a spherical GaAs quantum dot with a Gaussian confining potential are calculated by using the matrix diagonalization method. The size dependence of the exciton levels and the influence of the depth of the confining potential well in the spherical quantum dots are investigated. The same calculations performed with the parabolic approximation of the Gaussian potential lead to the results, which are qualitatively and quantitatively different.展开更多
The energy spectra of low-lying states of an exciton in a single and a vertically coupled quantum dots are studied under the influence of a perpendicularly applied magnetic field. Calculations are made by using the me...The energy spectra of low-lying states of an exciton in a single and a vertically coupled quantum dots are studied under the influence of a perpendicularly applied magnetic field. Calculations are made by using the method of numerical diagonalization of the Hamiltonian within the effective-mass approximation. We also calculated the binding energy of the ground and the excited states of an exciton in a single quantum dot and that in a vertically coupled quantum dot as a function of the dot radius for different vaJues of the distance and the magnetic field strength.展开更多
Making use of the adiabatic hyperspherical approach, we report a calculation for the energy spectrum of the ground and low-excited states of a two-dimensional helium in a magnetic field. The results show that the grou...Making use of the adiabatic hyperspherical approach, we report a calculation for the energy spectrum of the ground and low-excited states of a two-dimensional helium in a magnetic field. The results show that the ground and low-excited states of helium in low-dimensional space are more stable than those in three-dimensional space and there may exist more bound states.展开更多
基金The project supported by National Natural Science Foundation of China under Grant No.10275014
文摘The energy spectra of the ground state for an exciton (X) trapped by a neutral acceptor (A^o) in a quantumdot with a parabolic confinement have been calculated as a function of the electron-to-hole mass ratio σ by using thehyperspherical coordinates. We find that the (A^o, X) complex confined in a quantum dot has in general a larger bindingenergy than those in a two-dimensional quantum well and a three-dimensional bulk semiconductor, and the bindingenergy decreases with the increase of the electron-to-hole mass ratio.
文摘Two-electron states of a three-dimensional spherical GaAs quantum dot (QD) with a Gaussian confining potential confinement are studied. Calculations are made by using the method of few-body physics within the effectivemass approximation. We have calculated the energy levels of single and triplet states as functions of the range and depth of the confining potential well in the spherical QDs. The same calculations performed with the parabolic approximation of the Gaussian potential lead to the results, which are qualitatively and quantitatively different.
文摘We consider the problem of an electron-hole pair in a Gaussian confining potential well. This problem is treated within the effective-mass approximation framework using the method of numerical matrix diagonalization. The energy levels of the low-lying states are calculated as a function of the electron-hole effective mass ratio and the size of the confining potential.
文摘Making use of hyperspherical coordinates, we investigate the qualitative features of the ground and lowlying states of a positronium molecule confined in a two-dimensional (2D) space under a magnetic field. We find that a positronium molecule has more bound states in 2D than in 3D. With the increase of the magnetic field, the second bound state experiences a transition in angular momentum. The result shows that symmetry plays an essential role in the energy spectrum of low-lying states.
文摘The exciton L = 0 and L = 1 states of a spherical GaAs quantum dot with a Gaussian confining potential are calculated by using the matrix diagonalization method. The size dependence of the exciton levels and the influence of the depth of the confining potential well in the spherical quantum dots are investigated. The same calculations performed with the parabolic approximation of the Gaussian potential lead to the results, which are qualitatively and quantitatively different.
文摘The energy spectra of low-lying states of an exciton in a single and a vertically coupled quantum dots are studied under the influence of a perpendicularly applied magnetic field. Calculations are made by using the method of numerical diagonalization of the Hamiltonian within the effective-mass approximation. We also calculated the binding energy of the ground and the excited states of an exciton in a single quantum dot and that in a vertically coupled quantum dot as a function of the dot radius for different vaJues of the distance and the magnetic field strength.
文摘Making use of the adiabatic hyperspherical approach, we report a calculation for the energy spectrum of the ground and low-excited states of a two-dimensional helium in a magnetic field. The results show that the ground and low-excited states of helium in low-dimensional space are more stable than those in three-dimensional space and there may exist more bound states.
