We have studied the far-infrared spectra of two-electron vertically coupled quantum dots in an axial magnetic field by exact diagonalization. The calculated results show an obvious difference in role between the inter...We have studied the far-infrared spectra of two-electron vertically coupled quantum dots in an axial magnetic field by exact diagonalization. The calculated results show an obvious difference in role between the interactions for spin S = 1 and for spin S = O. The results support the possibility to evaluate the interactions by far-infrared spectroscopy in vertically coupled quantum dots.展开更多
The single photon scattering properties in a pair of waveguides coupled by a whispering-gallery resonator in- teracting with a semiconductor quantum dot are investigated theoretically. The two waveguides support four ...The single photon scattering properties in a pair of waveguides coupled by a whispering-gallery resonator in- teracting with a semiconductor quantum dot are investigated theoretically. The two waveguides support four possible ports for an incident single photon. The quantum dot is considered a V-type system. The incident direction-dependent single photon scattering properties are studied and equal-output probability from the four ports for a single photon incident is discussed. The influences of backscattering between the two modes of the whispering-gallery resonator for incident direction-dependent single photon scattering properties are also pre- sented.展开更多
By using the exact diagonalization method,a system of three electrons confined in a parabolic quantumdot in zero magnetic field is studied.The ground-state electronic structures and orbital and spin angular momentatra...By using the exact diagonalization method,a system of three electrons confined in a parabolic quantumdot in zero magnetic field is studied.The ground-state electronic structures and orbital and spin angular momentatransitions as a function of the confined strength are investigated.We find that the confinement may cause accidentaldegeneracies between levels with different low-lying states and the inversion of the energy values.The present,resultsare useful to understanding the optical properties and internal electron-electron correlations of quantum dot materials.展开更多
This paper studies the two-electron total energy and the energy of the electron-electron interaction by using a variational method of Pekar type on the condition of electric-LO-phonon strong coupling in a parabolic qu...This paper studies the two-electron total energy and the energy of the electron-electron interaction by using a variational method of Pekar type on the condition of electric-LO-phonon strong coupling in a parabolic quantum dot. It considers the following three cases: 1) two electrons are in the ground state; 2) one electron is in the ground state, the other is in the first-excited state; 3) two electrons are in the first-excited state. The relations of the two-electron total energy and the energy of the electron-electron interaction on the Coulomb binding parameter, the electron-LO-phonon coupling constant and the confinement length of the quantum dot are derived in the three cases.展开更多
By using the dispersion theory instead of the Frhlich Hamiltonian,the polaron energy in a quantum dot with a parabolic confinement potential is investigated at finite temperatures.It is found that the self-trapping ...By using the dispersion theory instead of the Frhlich Hamiltonian,the polaron energy in a quantum dot with a parabolic confinement potential is investigated at finite temperatures.It is found that the self-trapping energy of the polaron decreases with the increasing temperature,and the temperature effect is more obvious in quantum dots with weaker confinement.展开更多
<Abstract>In this paper,we study four electrons confined in a parabolic quantum dot in the absence of magnetic field,by the exact diagonalization method.The ground-state electronic structures and orbital and spi...<Abstract>In this paper,we study four electrons confined in a parabolic quantum dot in the absence of magnetic field,by the exact diagonalization method.The ground-state electronic structures and orbital and spin angular momenta transitions as a function of the confined strength are investigated.We find that the confinement may cause accidental degeneracies between levels with different low-lying states and the inversion of the energy values.The present results are useful to understand the optical properties and internal electron-electron correlations of quantum dot materials.展开更多
The temperature and LO phonon effects of the bipolaron in polar semiconductor quantum dots(QDs)are studied by using the Tokuda modified linear-combination operator method and the Lee-Low-Pines variational method.The e...The temperature and LO phonon effects of the bipolaron in polar semiconductor quantum dots(QDs)are studied by using the Tokuda modified linear-combination operator method and the Lee-Low-Pines variational method.The expressions for the mean number of LO phonons and the effective mass of the bipolaron are derived.Numerical results show that the mean number of LO phonons of the bipolaron decreases with increasing the temperature and the relative distance r between two electrons,but increases with increasing the electron-phonon coupling strengthα.The effective mass of the bipolaron M* increases rapidly with increasing the relative distance r between two electrons when r is smaller,and it reaches a maximum at r≈4.05r p,while after that,M*decreases slowly with increasing r.The effective mass of the bipolaron M*decreases with increasing the temperature.The electron-phonon coupling strengthαmarkedly influences the changes of mean number of LO phonons and the effective mass M*with the relative distance r and the temperature parameter γ.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No 10674084)
文摘We have studied the far-infrared spectra of two-electron vertically coupled quantum dots in an axial magnetic field by exact diagonalization. The calculated results show an obvious difference in role between the interactions for spin S = 1 and for spin S = O. The results support the possibility to evaluate the interactions by far-infrared spectroscopy in vertically coupled quantum dots.
基金Supported by the National Natural Science Foundation of China under Grant No 11105001the Anhui Provincial Natural Science Foundation under Grant Nos 1408085QA22 and 1608085MA09
文摘The single photon scattering properties in a pair of waveguides coupled by a whispering-gallery resonator in- teracting with a semiconductor quantum dot are investigated theoretically. The two waveguides support four possible ports for an incident single photon. The quantum dot is considered a V-type system. The incident direction-dependent single photon scattering properties are studied and equal-output probability from the four ports for a single photon incident is discussed. The influences of backscattering between the two modes of the whispering-gallery resonator for incident direction-dependent single photon scattering properties are also pre- sented.
基金The project supported by National Natural Science Foundation of China under Grant No.10475021
文摘By using the exact diagonalization method,a system of three electrons confined in a parabolic quantumdot in zero magnetic field is studied.The ground-state electronic structures and orbital and spin angular momentatransitions as a function of the confined strength are investigated.We find that the confinement may cause accidentaldegeneracies between levels with different low-lying states and the inversion of the energy values.The present,resultsare useful to understanding the optical properties and internal electron-electron correlations of quantum dot materials.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10747002)Inner Mongolia Universities Science Research Project (Grant No. NJzc08158)
文摘This paper studies the two-electron total energy and the energy of the electron-electron interaction by using a variational method of Pekar type on the condition of electric-LO-phonon strong coupling in a parabolic quantum dot. It considers the following three cases: 1) two electrons are in the ground state; 2) one electron is in the ground state, the other is in the first-excited state; 3) two electrons are in the first-excited state. The relations of the two-electron total energy and the energy of the electron-electron interaction on the Coulomb binding parameter, the electron-LO-phonon coupling constant and the confinement length of the quantum dot are derived in the three cases.
基金Supported by Shanghai Leading Academic Discipline Project(B408)National Key Project for Basic Research of China under Grant Nos.2010CB923203,2006CB806006,and 2006CB921105+1 种基金National Natural Science Foundation of China under Grant Nos.10904038 and 10874044Shanghai Municipal Science and Technology Commission under Grant Nos.09JC1404700 and 08PJ1404800
文摘By using the dispersion theory instead of the Frhlich Hamiltonian,the polaron energy in a quantum dot with a parabolic confinement potential is investigated at finite temperatures.It is found that the self-trapping energy of the polaron decreases with the increasing temperature,and the temperature effect is more obvious in quantum dots with weaker confinement.
基金supported by National Natural Science Foundation of China under Grant No.10775035
文摘<Abstract>In this paper,we study four electrons confined in a parabolic quantum dot in the absence of magnetic field,by the exact diagonalization method.The ground-state electronic structures and orbital and spin angular momenta transitions as a function of the confined strength are investigated.We find that the confinement may cause accidental degeneracies between levels with different low-lying states and the inversion of the energy values.The present results are useful to understand the optical properties and internal electron-electron correlations of quantum dot materials.
基金supported by the Science and Technology Development Plan of Qinhuangdao(No.201101A027)
文摘The temperature and LO phonon effects of the bipolaron in polar semiconductor quantum dots(QDs)are studied by using the Tokuda modified linear-combination operator method and the Lee-Low-Pines variational method.The expressions for the mean number of LO phonons and the effective mass of the bipolaron are derived.Numerical results show that the mean number of LO phonons of the bipolaron decreases with increasing the temperature and the relative distance r between two electrons,but increases with increasing the electron-phonon coupling strengthα.The effective mass of the bipolaron M* increases rapidly with increasing the relative distance r between two electrons when r is smaller,and it reaches a maximum at r≈4.05r p,while after that,M*decreases slowly with increasing r.The effective mass of the bipolaron M*decreases with increasing the temperature.The electron-phonon coupling strengthαmarkedly influences the changes of mean number of LO phonons and the effective mass M*with the relative distance r and the temperature parameter γ.