压缩态变分法研究抛物量子点中强耦合极化子的性质

The Properties of the Polaron in the Electron-phonon Strong-coupling Regime in a Parabolic Quantum Dot by Squeezed-state Variational Approach

研究了抛物量子点中强耦合极化子的性质。采用基于逐次正则变换的变分方法,利用单模压缩态变换处理包含声子产生湮灭算符的双线性项,得到了仅在考虑电子与体纵光学声子相互作用情况下,在电子-声子强耦合极限下抛物量子点中极化子的基态能量及电子周围光学声子平均数的数学表达式,并分别讨论了有效受限长度、电子-体纵光学声子耦合常数与基态能量和声子平均数之间的变化关系。

In the paper, the properties of the strong-coupling polaron in a parabolic quantum dot is studied. The variational approach applied is based on two successive canonical transforma- tions and a single-mode squeezed-state type unitary transformation is used to deal with the biline-ar terms involving phonon producing-vanishing operator. Obtained are the ground-state energy of polaron and the average number of virtual phonons around the electron in the electron-phonon strong-coupling regime in a parabolic quantum dot. Finally, their relationships with the effective confinement length and the coupling constant are discussed.