在声子色散影响下利用压缩态变分法计算了抛物量子点中弱耦合极化子的基态能量。采用的变分方法是基于逐次正则并且利用单模压缩态变换处理通常被我们所忽略的在第一次幺正变换中产生的声子产生湮灭算符的双线性项。计算得出了在考虑声子色散的情况下抛物量子点中弱耦合极化子的基态能量的数学表达式。讨论了抛物量子点中在电子-声子弱耦合情况下,受限长度,电子-声子耦合常数,色散系数与极化子基态能量之间的依赖关系。
The ground state energy of weak-coupling polaron in a parabolic quantum dot considering the phonon dispersion is calculated using the squeezed-state variational approach. The variational approach we applied is based on two successive canonical transformations and using a single-mode squeezed-state type unitary transformation to deal with the bilinear terms which we neglected usually. The relations of the ground-state energy of polaron in a parabolic quantum dot on the electron-LO-phonon coupling constant, the coefficient of phonon dispersion and the confinement length are derived in the electron-LO-phonon weak-coupling case.