声子色散对量子点中弱耦合磁极化子性质的影响(英文)

The influence of the phonon dispersion on the properties of weak-coupling magnetopolaron in a quantum dot

利用线性组合算符和幺正变换的方法,研究声子色散对磁场中抛物量子点弱耦合磁极化子性质的影响.计及LO声子色散,在抛物近似下导出了基态能量与量子点有效受限长度、声子色散系数、磁场强度以及耦合强度之间的关系.我们可以得到在弱耦合情况下抛物量子点中磁极化子的基态能量E0随量子点有效受限长度l0、电子声子耦合常数α和声子色散系数γ的增大而减小,随磁场回旋频率ωc增大而增大.自陷能Eotr随声子色散系数γ增大而增大.

With the use of linear-combination operator and unitary transformation method, the influence of the dispersion of phonons on the properties of weak-coupling rnagnetopolaron in a parabolic quantum dot is studied. Taking account of bulk LO phonons dispersion in a parabolic approximation, the ground state energy as a function of the effective confinement length, the coefficient of the phonon dispersion, the cyclotron-resonance frequency and the electron-phonon coupling constant are obtained. It is shown that in the electron-LO-phonon weak-coupling case, the ground state energy decreases with increasing the effective confinement length, the electron-LO-phonon coupling constant and the coefficient of the phonon dispersion; the ground state energy increases with increasing the cyclotron resonance frequency. The self-trapping energy becomes larger considering the influence of the phonon dispersion.