Based on the variational method of Pekar type, we study the energies and the wave-functions of the ground and the first-excited states of magneto-bipolaron, which is strongly coupled to the LO phonon in a parabolic po...Based on the variational method of Pekar type, we study the energies and the wave-functions of the ground and the first-excited states of magneto-bipolaron, which is strongly coupled to the LO phonon in a parabolic potential quantum dot under an applied magnetic field, thus built up a quantum dot magneto-bipolaron qubit. The results show that the oscillation period of the probability density of the two electrons in the qubit decreases with increasing electron–phonon coupling strength α, resonant frequency of the magnetic field ωc, confinement strength of the quantum dot ω0, and dielectric constant ratio of the medium η; the probability density of the two electrons in the qubit oscillates periodically with increasing time t, angular coordinate φ2, and dielectric constant ratio of the medium η; the probability of electron appearing near the center of the quantum dot is larger, and the probability of electron appearing away from the center of the quantum dot is much smaller.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
To study the influence of an anisotropic parabolic potential （APP） on the properties of a quantum dot （QD） qubit, we obtain the eigenenergies and eigenfunctions of the ground and first excited state of an electron...To study the influence of an anisotropic parabolic potential （APP） on the properties of a quantum dot （QD） qubit, we obtain the eigenenergies and eigenfunctions of the ground and first excited state of an electron, which is strongly coupled to the bulk longitudinal optical （LO） phonons, in a QD under the influence of an APP by the celebrated Lee-Low-Pines （LLP） unitary transformation and the Pekar type variational （PTV） methods. Then, this kind of two-level quantum system can be excogitated to constitute a single qubit. When the electron locates at the superposition state of its related eigenfunctions, we get the time evolution of the electron＇s probability density. Finally, the influence of an APP on the QD qubit is investigated. The numerical calculations indicate that the probability density will oscillate periodically and it is a decreasing function of the effective confinement lengths of the APP in different directions. Whereas its oscillatory period is an increasing one and will diminish with enhancing the electron-phonon （EP） coupling strength.展开更多
基金Project supported by the Natural Science Foundation of Hebei Province,China(Grant No.E2013407119)the Items of Institution of Higher Education Scientific Research of Hebei Province and Inner Mongolia,China(Grant Nos.ZD20131008,Z2015149,Z2015219,and NJZY14189)
文摘Based on the variational method of Pekar type, we study the energies and the wave-functions of the ground and the first-excited states of magneto-bipolaron, which is strongly coupled to the LO phonon in a parabolic potential quantum dot under an applied magnetic field, thus built up a quantum dot magneto-bipolaron qubit. The results show that the oscillation period of the probability density of the two electrons in the qubit decreases with increasing electron–phonon coupling strength α, resonant frequency of the magnetic field ωc, confinement strength of the quantum dot ω0, and dielectric constant ratio of the medium η; the probability density of the two electrons in the qubit oscillates periodically with increasing time t, angular coordinate φ2, and dielectric constant ratio of the medium η; the probability of electron appearing near the center of the quantum dot is larger, and the probability of electron appearing away from the center of the quantum dot is much smaller.
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 the National Natural Science Foundation of China(No.10964005)
文摘To study the influence of an anisotropic parabolic potential （APP） on the properties of a quantum dot （QD） qubit, we obtain the eigenenergies and eigenfunctions of the ground and first excited state of an electron, which is strongly coupled to the bulk longitudinal optical （LO） phonons, in a QD under the influence of an APP by the celebrated Lee-Low-Pines （LLP） unitary transformation and the Pekar type variational （PTV） methods. Then, this kind of two-level quantum system can be excogitated to constitute a single qubit. When the electron locates at the superposition state of its related eigenfunctions, we get the time evolution of the electron＇s probability density. Finally, the influence of an APP on the QD qubit is investigated. The numerical calculations indicate that the probability density will oscillate periodically and it is a decreasing function of the effective confinement lengths of the APP in different directions. Whereas its oscillatory period is an increasing one and will diminish with enhancing the electron-phonon （EP） coupling strength.
