共查询到17条相似文献,搜索用时 93 毫秒
1.
CHEN Shi-Hua XIAO Jing-Lin 《理论物理通讯》2008,50(12):1287-1289
On the condition of electric-LO phonon strong coupling in unsymmetrical parabolic confinement potential quantum dot (QD), we obtain the eigenenergies of the ground state and the first-excited state, the eigenfunctions of the ground state, and the first-excited state by using variational method of Pekar type. This system in QD may be employed as a two-level quantum system-qubit. When the electron is in the superposition state of the ground state and the first-excited state, we obtain the time evolution of the electron density. The relations both the probability density of electron and the period of oscillation with the electron-LO-phonon coupling strength, the confinement strengths in the xy-plane and the z-direction are discussed. 相似文献
2.
The Hamiltonian of a quantum rod with an ellipsoidal boundary is given by using a coordinate transformation in which the ellipsoidal boundary is changed into a spherical one.Under the condition of strong electron-longitudinal optical phonon coupling in the rod,we obtain both the electron eigenfunctions and the eigenenergies of the ground and first-excited state by using the Pekar-type variational method.This quantum rod system may be used as a two-level qubit.When the electron is in the superposition state of the ground and first-excited states,the probability density of the electron oscillates in the rod with a certain period.It is found that the oscillation period is an increasing function of the ellipsoid aspect ratio and the transverse and longitudinal effective confinement lengths of the quantum rod,whereas it is a decreasing function of the electron-phonon coupling strength. 相似文献
3.
On the condition of electric-LO phonon strong coupling in a parabolic quantum dot, we obtain the eigenenergy and the eigenfunctions of the ground state and the first-excited state using the variational method of Pekar type. This system in a quantum dot may be employed as a two-level quantum system-qubit. When the electron is in the superposition state of the ground state and the first-excited state, we obtain the time evolution of the electron density. The relations of the probability density of electron on the temperature and the electron-LO-phonon coupling constant and the relations of the period of oscillation on the temperature, the electron-LO-phonon coupling constant, the Coulomb binding parameter and the confinement length are derived. The results show that the probability density of electron oscillates with a period when the electron is in the superposition state of the ground and the first-excited state, and show that there are different laws that the probability density of electron and the period of oscillation change with the temperature and the electron-LO-phonon coupling constant when the temperature is lower or higher. And it is obtained that the period of oscillation decreases with increasing the Coulomb bound potential and increases with increasing the confinement length not only at lower temperatures but also at higher temperatures. 相似文献
4.
Properties of Parabolic Linear Bound Potential and Coulomb Bound Potential Quantum Dot Qubit 总被引:1,自引:0,他引:1
WANG Zi-Wu LI Wei-Ping YIN Ji-Wen XIAO Jing-Lin 《理论物理通讯》2008,49(2):311-314
On the condition of electric-LO phonon strong-coupling in a parabolic quantum dot, we obtain the eigenenergy of the ground-state and the first-excited state, the eigenfunctions of the ground-state and the first-excited state by using variational method of Pekar type. This system in quantum dot may be employed as a two-level quantum system-qubit. When the electron is in the superposition state of the ground- and the first-excited state, we obtain the time evolution of the electron density. The relation of the probability density of electron on the Coulomb binding parameter and the relations of the period of oscillation on the Coulomb binding parameter, the electron-LO-phonon coupling constant and the confinement length are derived. 相似文献
5.
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. 相似文献
6.
We study the eigenenergies and eigenfunctions of the ground and first-excited states of an electron which is strongly coupled to an LO-phonon in a quantum dot with a triangular bound potential and Coulomb bound potential by using the Pekar variational method. This system may be used as a two-level qubit. Phonon spontaneous emission causes the decoherence of the qubit. Numerical calculations are performed on the decoherence rate as a function of the polar angle, the Coulomb binding parameter, the coupling strength, the confinement length of the quantum dot and the dispersion coefficient. 相似文献
7.
《中国物理 B》2017,(1)
Within the frame of the Pavlov–Firsov spin–phonon coupling model, we study the spin-flip assisted by the acoustical phonon scattering between the first-excited state and the ground state in quantum dots. We analyze the behaviors of the spin relaxation rates as a function of an external magnetic field and lateral radius of quantum dot. The different trends of the relaxation rates depending on the magnetic field and lateral radius are obtained, which may serve as a channel to distinguish the relaxation processes and thus control the spin state effectively. 相似文献
8.
《中国物理 B》2016,(7)
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 ω_c, confinement strength of the quantum dot ω_0, 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 φ_2, 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. 相似文献
9.
This paper reports that the ground-state energy of polaron was obtained with strong electron-LO-phonon coupling by using a variational method of the Pekar type in a parabolic quantum dot. Quantum transition is occurred in the quantum system due to the electron-phonon interaction and the influence of temperature. That is the polaron transit from the ground-state to the first-excited state after absorbing a LO-phonon and it causes the change of the polaron lifetime. Numerical calculations are performed and the results illustrate that the ground-state lifetime of the polaron will increase with increasing the ground-state energy of polaron and decrease with increasing the electron-LO-phonon coupling strength, the confinement length of the quantum dot and the temperature. 相似文献
10.
This paper presents and implements a specified partial adiabatic search algorithm on a quantum circuit. It studies the minimum energy gap between the first excited state and the ground state of the system Hamiltonian and it finds that,in the case of M = 1,the algorithm has the same performance as the local adiabatic algorithm. However,the algorithm evolves globally only within a small interval,which implies that it keeps the advantages of global adiabatic algorithms without losing the speedup of the local adiabatic search algorithm. 相似文献
11.
12.
On the condition of electric-LO phonon strong coupling in parabolic quantum dot, we obtain the eigenenergies of the ground state and the first-excited state, the eigenfuctions of the ground state and the first-excited state by using variational method of Pekar type. This system in quantum dot may be employed as a two-level quantum system—qubit. The phonon spontaneous emission causes the decoherence of the qubit. The relations between the decoherence time with the coupling strength, the confinement length, the coefficient dispersion are discussed. 相似文献
13.
We study the eigenenergies and eigenfunctions of the ground and the first-excited states of an electron, which is strongly coupled to LO-phonon in a quantum dot with triangular bound potential by using the Pekar variational method. This system may be used as a two-level qubit. Numerical calculations are performed on the electron probability density varying with respect to the time, the temperature, the electron–LO-phonon coupling strength, the confinement length of the quantum dot and the polar angle. The relationship between the oscillating period and the polar angle is derived. 相似文献
14.
We study the eigenenergies and the eigenfunctions of the ground and the first excited states of an electron, which is strongly coupled to LO-phonon in a quantum rod with a hydrogen-like impurity at the center by using the variational method of Pekar type. This quantum rod system may be used as a two-level quantum qubit. When the electron is in the superposition state of the ground and the first-excited states, the probability density of the electron oscillates in the quantum rod. It is found that the probability density and the oscillation period are individually increased and decreased due to the presence of the Coulomb interaction between the electron and the hydrogen-like impurity. The oscillation period is an increasing function of the ellipsoid aspect ratio and the effective confinement lengths of the quantum rod, whereas it is a decreasing one of the electron–phonon coupling strength. 相似文献
15.
16.
Yi-Fu Yu Wei-Ping Li Ji-Wen Yin Jing-Lin Xiao 《International Journal of Theoretical Physics》2011,50(11):3322-3328
On the condition of electric-LO phonon strong coupling in parabolic quantum dot, we obtain the eigenenergies of the ground
state and the first-excited state, the eigenfunctions of the ground state and the first-excited state by using variational
method of Pekar type. This system in quantum dot may be employed as a two-level quantum system-qubit. The phonon spontaneous
emission causes the decoherence of the qubit. We displayed the density matrix of the qubit decayed with the time evolution
and the coherence term of the density matrix element p
10 (or p
01) decayed with the time evolution for different coupling strength, the confinement length, the coefficient dispersion. 相似文献
17.
Wei-Ping Li Ji-Wen Yin Yi-Fu Yu Jing-Lin Xiao Zi-Wu Wang 《International Journal of Theoretical Physics》2009,48(12):3339-3344
The time evolution of the quantum mechanical state of an electron is calculated by using variational method of Pekar type
on the condition of electric-LO phonon strong coupling in a parabolic quantum dot. We obtained the eigen energies of the ground
state and the first-excited state, the eigen functions of the ground state and the first-excited state this system in a quantum
dot may be employed as a two-level quantum system-qubit. The supposition electron is in system’s ground state in the initial
time, the electron transit from the ground state to the excited state in presence of an electric field F along the x axis. The results indicate that the electron transition probability and the oscillation period increase with decreasing the
electron-LO-phonon coupling constant, increasing the electric field and the confinement length. 相似文献